Multiplexed pneumatic control air system for slurry filtration

ABSTRACT

An automated computer-controlled sampling system and related methods for collecting, processing, and analyzing agricultural samples for various chemical properties such as plant available nutrients. The sampling system allows multiple samples to be processed and analyzed for different analytes or chemical properties in a simultaneous concurrent or semi-concurrent manner. Advantageously, the system can process soil samples in the “as collected” condition without drying or grinding. The system generally includes a sample preparation sub-system which receives soil samples collected by a probe collection sub-system and produces a slurry (i.e. mixture of soil, vegetation, and/or manure and water), and a chemical analysis sub-system which processes the prepared slurry samples for quantifying multiple analytes and/or chemical properties of the sample. The sample preparation and chemical analysis sub-systems can be used to analyze soil, vegetation, and/or manure samples. A soil collection system is disclosed which captures and directs samples to the sampling system for processing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Nos.63/017,789, filed 30 Apr. 2020; 63/018,120, filed 30 Apr. 2020;63/018,153, filed 30 Apr. 2020; and 63/017,840, all of which areincorporated herein by reference in their entireties.

BACKGROUND

The present disclosure relates generally to agricultural sampling andanalysis, and more particularly to a fully automated system forperforming soil and other types of agricultural related sampling andchemical property analysis.

Periodic soil testing is an important aspect of the agricultural arts.Test results provide valuable information on the chemical makeup of thesoil such as plant-available nutrients and other important properties(e.g. 1evels of nitrogen, magnesium, phosphorous, potassium, pH, etc.)so that various amendments may be added to the soil to maximize thequality and quantity of crop production.

In some existing soil sampling processes, collected samples are dried,ground, water is added, and then filtered to obtain a soil slurrysuitable for analysis. Extractant is added to the slurry to pull outplant available nutrients. The slurry is then filtered to produce aclear solution or supernatant which is mixed with a chemical reagent forfurther analysis.

Improvements in testing soil, vegetation, and manure are desired.

BRIEF SUMMARY

The present disclosure provides an automated computer-controlledsampling system and related methods for collecting, processing, andanalyzing soil samples for various chemical properties such as plantavailable nutrients (hereafter referred to as a “soil sampling system”).The sampling system allows multiple samples to be processed and analyzedfor different analytes (e.g. plant-available nutrients) and/or chemicalproperties (e.g. pH) in a simultaneous concurrent or semi-concurrentmanner, and in relatively continuous and rapid succession.Advantageously, the system can process soil samples in the “ascollected” condition without the drying and grinding steps previouslydescribed.

The present system generally includes a sample preparation sub-systemwhich receives soil samples collected by a probe collection sub-systemand produces a slurry (i.e. mixture of soil, vegetation, and/or manureand water) for further processing and chemical analysis, and a chemicalanalysis sub-system which receives and processes the prepared slurrysamples from the sample preparation sub-system for quantification of theanalytes and/or chemical properties of the sample. The describedchemical analysis sub-system can be used to analyze soil, vegetation,and/or manure samples.

In one embodiment, the sample preparation system generally includes amixer-filter apparatus which mixes the collected raw soil sample in the“as sampled” condition (e.g. undried and unground) with water to form asample slurry. The mixer-filter apparatus then filters the slurry duringits extraction from the apparatus for processing in the chemicalanalysis sub-system. The chemical analysis sub-system processes theslurry and performs the general functions of extractant andcolor-changing reagent addition/mixing, centrifugating the slurry sampleto yield a clear supernatant, and finally sensing or analysis fordetection of the analytes and/or chemical properties such as viacolorimetric analysis.

Although the sampling systems (e.g. sample collection, preparation, andprocessing) may be described herein with respect to processing soilsamples which represents one category of use for the disclosedembodiments, it is to be understood that the same systems including theapparatuses and related processes may further be used for processingother types of agricultural related samples including without limitationvegetation/plant, forage, manure, feed, milk, or other types of samples.The disclosure herein should therefore be considered broadly as anagricultural sampling system. Accordingly, the present disclosure isexpressly not limited to use with processing and analyzing soil samplesalone for chemical properties of interest.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description and the accompanying drawings, wherein likeelements are labeled similarly and in which:

FIG. 1A is a basic schematic diagram of a first embodiment of anagricultural sample analysis system;

FIG. 1B is a basic schematic diagram of a second embodiment of anagricultural sample analysis system including closed flow loop slurryrecirculation;

FIG. 2 is a perspective view of a first embodiment of a slurry densitymeter usable in the systems of FIGS. 1A or 1B;

FIG. 3 is a first side view thereof;

FIG. 4 is a second side view thereof;

FIG. 5 is a first end view thereof;

FIG. 6 is a second end view thereof;

FIG. 7 is top view thereof;

FIG. 8 is a bottom view thereof;

FIG. 9 is a first longitudinal cross sectional view thereof;

FIG. 10 is a second longitudinal cross sectional view thereof;

FIG. 11 is a longitudinal perspective cross sectional view thereof;

FIG. 12 is a first perspective view of a second embodiment of a slurrydensity meter usable in the systems of FIGS. 1A or 1B;

FIG. 13 is a second perspective view thereof;

FIG. 14 is a third perspective view thereof with control systemcircumference board detached;

FIG. 15 is a longitudinal cross sectional view thereof;

FIG. 16A shows a portion of the oscillator tube of the density meterillustrating accumulation of iron particles in the slurry on the insideof the tube caused by the magnetic field of a permanent magnet attachedto the tube;

FIG. 16B shows a first embodiment of a magnetic isolation memberattached to the oscillator tube;

FIG. 16C shows a second embodiment of a magnetic isolation memberattached to the oscillator tube;

FIG. 16D shows a third embodiment of a magnetic isolation memberattached to the oscillator tube;

FIG. 16E shows a fourth embodiment of a magnetic isolation memberattached to the oscillator tube;

FIG. 16F shows possible directional vibrational motions for theoscillator tube;

FIG. 16G shows an oscillator tube mounted in a vertically orientation;

FIG. 17 is a first perspective view of a first embodiment of a finefilter unit;

FIG. 18 is a second perspective view thereof;

FIG. 19 is a bottom view thereof;

FIG. 20 is top view thereof;

FIG. 21 is a side cross sectional view thereof;

FIG. 22 is a first perspective view of a second embodiment of a finefilter unit;

FIG. 23 is a second perspective view thereof;

FIG. 24 is an end view thereof;

FIG. 25 is a top view thereof;

FIG. 26 is side cross sectional view thereof;

FIG. 27 is a schematic diagram of a pump-less system for blending a soilslurry using pressurized air;

FIG. 28 is a first graph showing dilution amount of diluent (e.g. water)added to the slurry versus slurry density;

FIG. 29 is a second graph thereof; and

FIG. 30 is a third graph thereof.

FIG. 31 is a top view of an alternative embodiment of the micropump ofthe microfluidic processing disk comprising a plurality of inlet andoutlet ports formed in the lower chamber;

FIG. 32 is a perspective view of an analysis processing wedge of themicrofluidic processing disk comprising an alternative embodiment of amicropump including diaphragm restraining tabs;

FIG. 33 is a perspective view of the active layer of the analysisprocessing wedge comprising the lower part of the micropump;

FIG. 34 is a top view thereof;

FIG. 35 is an enlarged view taken of the micropump taken from FIG. 34 ;

FIG. 36 is a transverse cross-sectional view thereof taken from FIG. 35;

FIG. 37 is a top perspective view of the lower chamber of the micropumpof FIG. 35 ;

FIG. 38 is a perspective view of a pressure-amplified electro-pneumaticcontrol air valve;

FIG. 39 is a top view thereof;

FIG. 40 is a transverse cross-sectional view thereof;

FIG. 41 is a top view of the analysis processing wedge showing a fluidlyinterconnected micropump array;

FIG. 42 is a schematic diagram of a multiplexed control air system usingmultiple pressure-amplified electro-pneumatic control air valves of FIG.38 to control operation of an ultrafine filter unit;

FIG. 43 is a side transverse cross-sectional view of the ultrafinefilter unit;

FIG. 44 is a perspective view of one embodiment of a mobile soilcollection sample system according to the present disclosure;

FIG. 45 is a rear top perspective view of a collection assembly thereof;

FIG. 46 is a front top perspective view thereof;

FIG. 47 is an enlarged detail view from FIG. 46 ;

FIG. 48 is a horizontal transverse cross-sectional view of the knifeassembly of the collection assembly of FIG. 45 ;

FIG. 49 is a rear bottom perspective view of the collection assembly;

FIG. 50 is a front bottom perspective view thereof;

FIG. 51 is a front view thereof;

FIG. 52 is a rear view thereof;

FIG. 53 is a left side view thereof;

FIG. 54 is a right side view thereof;

FIG. 55 is a top view thereof;

FIG. 56 is a bottom view thereof;

FIG. 57 is a rear exploded view of the collection apparatus of thecollection assembly;

FIG. 58 is a front exploded view thereof;

FIG. 59 is a top exploded perspective view of a portion of thecollection spool drive mechanism of the collection apparatus;

FIG. 60 is a bottom exploded perspective view thereof;

FIG. 61 is an assembled perspective view of gear drive of the spooldrive mechanism;

FIG. 62 is perspective view of the driven gear thereof coupled to thecollection spool;

FIG. 63 is a bottom perspective view of the driven gear assembly;

FIG. 64 is a top perspective view thereof;

FIG. 65 is a side cross-sectional view of the gear drive;

FIG. 66 is a perspective view of gear drive showing the drive and drivengears;

FIG. 67 is a first side view of the collection apparatus in an activelower soil sample collection position engage with the soil with thecollection apparatus in a first angular rotated position;

FIG. 68 is a second side view thereof with the collection apparatus in asecond angular rotated position;

FIG. 69 is a side view of the collection apparatus in an upper stowedposition;

FIG. 70 is a front perspective view of a carriage chassis of thecollection assembly supporting a rolling carriage to which thecollection apparatus is mounted;

FIG. 71 is a rear perspective view thereof;

FIG. 72 is a front view thereof;

FIG. 73 is a rear view thereof;

FIG. 74 is right side view thereof;

FIG. 75 is a top view thereof;

FIG. 76 is a bottom view thereof;

FIG. 77 is a rear exploded view thereof;

FIG. 78 is a front exploded view thereof;

FIG. 79 is a rear perspective view of the carriage with wheels orrollers and guide rails with the outer carriage frame removed forclarity;

FIG. 80 is a front perspective view thereof;

FIG. 81 is a perspective view of the collection spool of the collectionapparatus;

FIG. 82 is an enlarged perspective view thereof;

FIG. 83 is a rear perspective view of an alternative two spoolembodiment of a collection apparatus showing the gear drive of the spooldrive mechanism;

FIG. 84 is a rear perspective view thereof with the gear drive motorsmounted;

FIG. 85 is a top perspective view of a portion of the gear box and oneof the driven gears and collection spool;

FIG. 86 is an exploded perspective view thereof;

FIG. 87 is a left side view of the knife assembly of the collectionapparatus showing the spool drive mechanism with spool positioningactuator support frame removed;

FIG. 88 is a left side view thereof with support frame;

FIG. 89 is a first left side perspective view of the knife assembly;

FIG. 90 is a second left side perspective view thereof;

FIG. 91 is a horizontal transverse cross-sectional view of the two spoolknife assembly;

FIG. 92 is an exploded perspective view of the driven gear assembly;

FIG. 93 is an assembled view thereof;

FIG. 94 is a schematic diagram showing a complete spool operating cyclefor either the single or double spool embodiments.

All drawings are not necessarily to scale. Components numbered andappearing in one figure but appearing un-numbered in other figures arethe same unless expressly noted otherwise. A reference herein to a wholefigure number which appears in multiple figures bearing the same wholenumber but with different alphabetical suffixes shall be constructed asa general refer to all of those figures unless expressly notedotherwise.

Any reference to a drawing number preceded by “P-” is a reference to thesame drawing number in WO2020/012369.

DETAILED DESCRIPTION

The features and benefits of the present disclosure are illustrated anddescribed herein by reference to exemplary (“example”) embodiments. Thisdescription of exemplary embodiments is intended to be read inconnection with the accompanying drawings, which are to be consideredpart of the entire written description. Accordingly, the disclosureexpressly should not be limited to such exemplary embodimentsillustrating some possible non-limiting combination of features that mayexist alone or in other combinations of features.

In the description of embodiments disclosed herein, any reference todirection or orientation is merely intended for convenience ofdescription and is not intended in any way to limit the scope of thepresent disclosure. Relative terms such as “lower,” “upper,”“horizontal,” “vertical,”, “above,” “below,” “up,” “down,” “top” and“bottom” as well as derivative thereof (e.g., “horizontally,”“downwardly,” “upwardly,” etc.) should be construed to refer to theorientation as then described or as shown in the drawing underdiscussion. These relative terms are for convenience of description onlyand do not require that the apparatus be constructed or operated in aparticular orientation. Terms such as “attached,” “affixed,”“connected,” “coupled,” “interconnected,” and similar refer to arelationship wherein structures are secured or attached to one anothereither directly or indirectly through intervening structures, as well asboth movable or rigid attachments or relationships, unless expresslydescribed otherwise.

As used throughout, any ranges disclosed herein are used as shorthandfor describing each and every value that is within the range. Any valuewithin the range can be selected as the terminus of the range. Inaddition, all references cited herein are hereby incorporated byreferenced in their entireties. In the event of a conflict in adefinition in the present disclosure and that of a cited reference, thepresent disclosure controls.

The following applications are incorporated herein by reference in theirentireties: International Application No. PCT/IB2019/055862 filed Jul.10, 2019, which claims the benefit of priority to U.S. ProvisionalPatent Application No. 62/696,271 filed Jul. 10, 2018, U.S. ProvisionalPatent Application No. 62/729,623 filed Sep. 11, 2018, U.S. ProvisionalPatent Application No. 62/745,606 filed Oct. 15, 2018, U.S. ProvisionalPatent Application No. 62/792,987 filed Jan. 15, 2019, U.S. ProvisionalPatent Application No. 62/829,807 filed Apr. 5, 2019, U.S. ProvisionalPatent Application No. 62/860,297 filed Jun. 12, 2019.

Chemical can be a solvent, an extractant, and/or a reagent. Solvent canbe any fluid to make a slurry as described herein. In a preferredembodiment, the solvent is water because it is readily available, butany other solvent can be used. Solvent can be used as both a solvent andan extractant. Gas can be any gas. In a preferred embodiment, the gas isair because it is readily available, but any gas can be used.

Test material refers to supernatant, filtrate, or a combination ofsupernatant and filtrate. When used in this description in the specificform (supernatant or filtrate), the other forms of test material canalso be used.

Fluid conveyor can be a pump, a pressure difference, or a combination ofa pump and pressure difference.

Microfluidic Slurry Processing System Modifications

FIGS. 33-37 depict a modification of the pneumatically-actuateddiaphragm micropump 5760 such as shown in FIGS. P-256 to P-258previously described herein. This micropump is an integral device of theanalysis processing wedges 312 of microfluidic processing disk 310.Micropump 5760 may be used for the extractant pump 330, slurry pump 331,reagent pump 332, transfer pump 333, or other pumps that may be requiredby the microfluidic agricultural sample slurry processing and analysissystem. These micropumps are incorporated into the microchannel network325 of the microfluidic device, which may be a processing wedge 312 ofmicrofluidic processing disk 310 previously described herein. Themicropumps apply the motive force to the fluid to drive it through themicrochannel network and various flow-related features of the disk. Itbears noting that in some other implementations, the micropumps may beembodied in a microfluidic manifold of any suitable polygonal ornon-polygonal configuration rather than a processing wedge. Accordingly,the microfluidic devices including the micropumps are expressly notlimited to wedge-shaped devices, which may be part of a microfluidicprocessing disk. The term “microfluidic device” should therefore bebroadly construed; the processing wedge being used only as onenon-limiting example of a microfluidic device for convenience ofreference.

According to another aspect of the disclosure, a diaphragm restraintfeature for forming the diaphragm-operated micropumps 5760 may beprovided which prevents spreading of the flexible diaphragm 5763material when the adjoining upper and lower layers 5761, 5762 of themulti-layered microfluidic processing disk 310 that define thepressure-retention boundaries of micropump are compressed and joinedtogether. This prevents the peripheral edges of the diaphragm frommigrating outwards beyond the outer confines of the recess formed by thelower pump chamber 5765 in the lower layer 5762, which might prevent aproper leak-resistant seal from being formed around the diaphragm andlower pump chamber necessary for pneumatically pressuring the micropumpduring operation.

FIGS. 33-37 illustrate one non-limiting embodiment of a diaphragmrestraint feature for micropump 7510. Micropump 7510 in one embodimentmay therefore include a plurality of spaced apart and inwardlyprotruding restraining tabs 7500 (further described below) positionedaround the perimeter of the upper chamber 5764 of the micropump. Aperimetrically extending sealing channel 7505 is recessed into the upperlayer 5761 (e.g. a first layer) around the perimeter of the upper pumpchamber 5764. The lower layer 5762 previously described herein (see,e.g. FIGS. P-256 to P-258) may be considered the second layer which isinterfaced with the first or upper layer. The channel 7505 is separatedfrom the main central recess 7506 of the upper pump chamber 5764 by araised protruding annular lip 7502 arranged at the inner edge of thesealing channel 7505. Lip 7502 supports the peripheral portion ofdiaphragm 5763 when positioned on the upper layer 5761 until the layersare compressed and assembled together. The main central recess 7506defines the flat top surface 5764-2 of the upper pump chamber 5764 aspreviously described herein (see, also FIGS. P-257 to P-258).Preferably, but not necessarily the restraining tabs 7500 are disposedon the microfluidic device layer have the flat chamber such as upperlayer 5761. FIGS. 33-37 show the upper layer 5761 on bottom as themicrofluidic device or disk in the assembling position to keep thediaphragm centered between the tabs 7500 until upper and lower layersare attached to each other. This is opposite to the positions of themicrofluidic processing disk upper and lower layers shown in FIGS. P-257to P-258 which is not necessarily an assembling position.

The present micropump 7510 operates to pump fluid in the same mannerpreviously described herein for micropump 5760. It also bears notingthat although not shown in FIGS. 32-37 , the lower pump chamber 5765opposite the reconfigured upper pump chamber 5764 which is shown mayoptionally incorporate the anti-stall grooves 5769 already describedelsewhere herein and shown in FIGS. P-256 to P-258.

The restraining tabs 7500 protrude radially inwards from the upper layer5761 of the micropump 7510 in the microfluidic processing disk into theupper pump chamber 5764 and sealing channel 7505 as shown. Tabs 7500 mayhave any suitable polygonal or non-polygonal shape, or a combinationthereof. In one non-limiting embodiment as illustrated, tabs 7500 mayeach have a flat inner surface formed between a pair of arcuately curvedside surfaces connected to the upper layer 5761 (best shown in FIG. 35). The tabs may be integrally formed as a unitary structural part of theupper layer 5761; the layers of the microfluidic processing disk 310being formed of a preferably clear polymeric material adhered togetheras previously described herein. Sealing channel 7505 comprises anupwardly open recess for receiving the diaphragm material at leastpartially therein when the diaphragm is compressed between the upper andlower layers 5761, 5762 as the multiple layers of the analysisprocessing wedges 312 of the microfluidic processing disk 310 areassembled. This forms a leak-resistant seal around the diaphragm andmicropump 7510.

FIG. 35 shows the diaphragm 5763 (shown in dashed lines) positioned inthe upper pump chamber 5764 of the micropump 7510 and ready for assemblybetween the adjoining upper and lower layers 5761, 5762 of themicrofluidic processing disk. The peripheral edges 5763-3 of diaphragm5763 are shown lightly contacting and engaging the inner edges orsurfaces of the inwardly protruding restraining tabs 7500 to properlylocate the diaphragm. When the disk upper and lower layers arecompressed together with the diaphragm therebetween, the deformablediaphragm will flatten out and try to grow radially outwards in alldirection, but its growth is restrained by restraining tabs 7500. Thisprevents outward migration of diaphragm 5763 beyond sealing channel 7505which can adversely affect the sealing to ensure that a properleak-resistant seal is formed around the micropump 7510.

A process or method for assembling a micropump for a microfluidic devicemay be summarized as generally comprising: providing a first layerincluding a first pump chamber; positioning a resiliently deformablediaphragm on the first layer above the first pump chamber; positioning asecond layer on the first layer and diaphragm; compressing the diaphragmbetween the first and second layers which causes the diaphragm to growradially outwards; and engaging peripheral edges of the diaphragm with aplurality of restraining tabs arranged around the first pump chamber torestrain the outward growth of the diaphragm.

In one embodiment, a microfluidic pump for a microfluidic device may beconsidered to generally comprise a first layer, a second layer adjacentthe first layer, a resiliently flexible diaphragm arranged at aninterface between the first and second layers, the diaphragm having aperipheral edge extending perimetric ally around the diaphragm, a firstpump chamber formed on a first side of the diaphragm and a second pumpchamber formed on a second side of the diaphragm, and a plurality ofrestraining tabs protruding radially inwards from the first layer intothe first pump chamber. The restraining tabs abuttingly engage theperipheral edge of diaphragm to restrain the diaphragm.

Analysis Flow Cell Angled Flow Path

According to another aspect of the flow analysis cells 4150, 3800, or337, the central flowpath and internal flow conduit extending throughthe portion or zone of the cells where the analyte measurement isobtained (e.g. flow cell window 4157, FIG. P-129) preferably is orientedat an angle to a horizontal reference plane Hp which can be imagined aspassing through and including elongated the geometric center of the flowcell window 4157 in the referenced figure. In FIG. P-129, the flow cellwindow 4157 is oriented horizontally and parallel to the horizontalreference plane Hp. However, an angled orientation of the flow cellwindow is advantageous because any bubbles within the sample fluid (e.g.supernatant) will interfere with and disrupt the measurement reading.When the fluid flowpath of the measurement portion of the flow cell isvertical or mostly vertical, however, any air bubbles carrying over fromupstream flow components (e.g. pumps, micropumps, mixing chambers, etc.)will float to the top due to their buoyancy. This carries the airbubbles through and out of the optical measurement path of the flow cellwhich do not become lodged or accumulate in close proximity to themeasurement light path in the flow cell window 4157 (see, e.g. FIG.P-129). Fluid velocity complemented by bubble buoyancy keep bubbles insuspension and moving along the flow path until they rise out of theoptical measurement zone. Without this combination, bubbles have atendency to stick to flow path walls and surface tension makes itdifficult to clear them.

Accordingly, the flow cell windows (e.g. flow cell window 4157) formeasuring the analyte of any of the embodiments of flow cells disclosedherein in various embodiments may be oriented between 0 and 90 degreesto the horizontal reference plane Hp, preferably at least 30 degrees tothe horizontal reference plane. In some embodiments, the flow cellanalysis window may be oriented vertically or 90 degrees to thehorizontal reference plane. This may be achieved in some embodiments byorienting the entire flow analysis cells or component in which the flowcell is located at an angle to the horizontal reference plane so thatthe measurement flow cell window is concomitantly oriented at an angleto the horizontal reference plane. This can be illustrated withreference to FIG. P-129 as an example. Flow analysis cell 4150 would beoriented at an angle so that the central flow cell window 4157 throughwhich the colorimetric measurement light passes achieves the foregoingpreferred angular orientation to horizontal reference plane Hp. In thecase of the flow analysis cell 337 integrally formed within the layersof analysis processing wedges 312 of microfluidic processing disk 310(see e.g. FIG. P-263), the entire wedge or disk is orientated angularlyto the horizontal reference plane to position the analysis flow cellwindow angularly to the horizontal reference plane.

In addition to having the fluid flow path of the measurement portion ofthe flow analysis cell (i.e. flow cell window) similarly angularlyoriented to the horizontal reference plane Hp such as nearly vertical insome embodiments, it is advantageous to also have whichever fluidchamber is immediately upstream of the flow cell similarly angled orvertical. This upstream fluid chamber can be a diaphragm pump, holdingchamber, fluid passage, or any other chamber that allows gravity andbuoyancy to separate bubbles from the flow path as fluid is drawn frompreferably a lower portion of the chamber. This minimizes or preventsair bubbles from reaching the flow analysis cell devices in the firstinstance. This may be achieved by specifically orienting the upstreamchamber preferably at least 30 degrees to the horizontal reference planeand about vertically (i.e. 90 degrees thereto) in some embodiments. Insome embodiments, an air removal device such as without limitation acommercially-available bubble trap may be used upstream of thenon-microfluidic processing disk flow analysis cells 4150 or 3800disclosed herein either instead of or in addition to angularly orientingthe flow cell windows of these analysis cells.

The sections which follow describe various modifications to theforegoing agricultural sample analysis systems and associated devicespreviously described herein which process and analyze/measure theprepared agricultural sample slurry for analytes of interest (e.g. soilnutrients such as nitrogen, phosphorous, potassium, etc., vegetation,manure, etc.). Specifically, the modifications relate to samplepreparation sub-system 3002 and chemical analysis sub-system 3003portions of soil sampling system 3000 shown in FIG. P-1. To providebroad context for discussion of the alternative devices and equipmentwhich follows, FIG. 1A is a high-level schematic system diagramsummarizing the agricultural sample analysis system process flowsequence. This embodiment illustrates static slurry batch mode densitymeasurement as further described herein. FIG. 1B is the same, butincludes a slurry recirculation loop between the fine filtration stationand sample preparation mixing chamber for dynamic continuous mode slurrydensity measurement.

Referring now to FIGS. 1A and 1B, agricultural sample analysis systems7000 includes in flow path sequence soil sample preparation sub-system7001, density measurement sub-system 7002, fine filtration sub-system7003, analyte extraction sub-system 7004, ultrafine filtrationsub-system 7005, and measurement sub-system 7006. Soil samplepreparation sub-system 7001 represents the portion of the system wheresample slurry is initially prepared. Accordingly, sub-system 7001 maycomprise any one of mixer-filter apparatus 100 or 200 previouslydescribed herein which includes the mixing chamber (e.g. mixing chamber102 or mixing cavity 207 a respectively) where water is added to thebulk soil sample to prepare the slurry, and a coarse filter (e.g. filter146 or flow grooves 218 on stopper 210) which removes larger particles(e.g. small stone, rocks, debris, etc.) from the prepared soil slurry.In addition, the coarse filter is sized to pass the desired maximumparticle size in the slurry to ensure uniform flow and density of theslurry for weight/density measurement used in the process, as furtherdescribed herein. The prepared slurry may be transferred from themixer-filter apparatus to the density measurement sub-system 7002 viapumping by slurry pump 7081, or alternatively via pressurizing themixer-filter apparatus chamber 102/207 a with pressurized air providedby a fluid coupling to a pressurized air source 7082 (shown in dashedlines in FIG. 1A).

The analyte extraction sub-system 7004 and measurement sub-system 7006may comprise the soil sampling system 3000 shown in FIGS. P-1, P-79 toP-94, and P-261 and previously described herein, or the microfluidicprocessing disk 310 arranged in the carousel assembly with analysisprocessing wedges 312 shown in FIGS. P-96 to P-121 and previouslydescribed herein. The ultrafine filtration sub-system 7005 may compriseultrafine filter 5757 shown in FIGS. P-261 to P-262 (associated withsoil sampling system 3000) or FIG. P-263 (associated with microfluidicprocessing disk 310). These systems and associated devices have beenalready described in detail and will not be repeated here for the sakeof brevity.

It bears noting that the order of the devices and equipment shown inFIGS. 1A-B (e.g. pump(s), valves, etc.) can be switched and relocated inthe systems without affecting the function of the unit. Moreover,additional devices and equipment such as valving, pumps, other flowdevices, sensors (e.g. pressure, temperature, etc.) may be added controlfluid/slurry flow and transmit additional operating information to thesystem controller which may control operation of the systems shown.Accordingly, the systems are not limited to the configuration anddevices/equipment shown alone.

Digital Slurry Density Measurement Devices

Density measurement sub-system 7002 comprises a digital slurry densitymeasurement device 7010 for obtaining the density of the mixedagricultural sample slurry prepared in sample preparation chamber (e.g.mixer-filter apparatus 100) of FIGS. 1A-B. In one implementation,density measurement device 7010 may be a digital density meter of theU-tube oscillator type shown in FIGS. 2-16 used to measure density ofthe sample slurry, which may be a soil slurry in one non-limitingexample which will be used hereafter for convenience in describing onepossible use recognizing that other type of agricultural samples may beprocessed such as plant waste, manure, etc. as previously describedherein. It should be recognized that any type of agricultural sampleslurry however may be processed in the same system including soil,vegetation, manure, or other. The density of the slurry is used todetermine the amount of diluent required (e.g. water) to be added to thesoil sample in order to achieve the desired water to soil ratio forchemical analysis of an analyte, as further described herein. TheU-shaped oscillator tube 7011 is excited via a frequency transmitter ordriver 7012 to oscillate the tube at its characteristic naturalfrequency. In various embodiments, the driver 7012 may be anelectromagnetic inductor, a piezoelectric actuator/element, or amechanical pulse generator all of which are operable to generate auser-controllable and preprogrammed excitation frequency. Acorresponding sensor such as a receiver or pickup 7013 is provided whichis configured to detect and obtain a vibrational measurement of theoscillator tube when excited. The pickup may be electromagnetic,inductance, piezoelectric receiver/element, optical, or othercommercially available sensor capable of detecting and measuring thevibrational frequency response of the oscillator tube 7011 when excited.The pulsing or vibrational response movement of the excited oscillatortube 7011 is detected pickup 7013 which measures the amplitude of thefrequency response of the tube, which is highest at a natural/resonanceor secondary harmonic frequency when the tube is empty. Alternatively,the phase difference between the driving and driven frequencies may beused to narrow into the natural frequency.

In operation, the vibrational frequency of oscillator tube 7011 whenexcited changes relative to the density of the slurry either stagnantlyfilled in the oscillator tube for batch mode density measurement in oneembodiment, or flowing through the U-tube at a preferably continuous andconstant flow rate for continuous density measurement in anotherembodiment. The digital density measurement device converts the measuredoscillation frequency into a density measurement via a digitalcontroller which is programmed to compare the baseline natural frequencyof the empty tube to the slurry filled tube.

The frequency driver and pickup 7012, 7013 are operably and communicablycoupled to an electronic control circuit comprising amicroprocessor-based density meter processor or controller 7016-2mounted to a circuit control board 7016 supported from base 7014.Controller 7016-2 is configured to deliver a pulsed excitation frequencyto the oscillator tube 7011 via the driver 7012, and measure theresultant change in the resonant frequency and phase of the excitedoscillator tube. The digital density measurement device 7010 convertsthe measured oscillation frequency into a density measurement via thecontroller which is preprogrammed and configured with operating softwareor instructions to perform the measurement and density determination.The controller 7016-2 may be provided and configured with all of theusual ancillary devices and appurtenances similar to any of thecontrollers already previously described herein and necessary to providea fully functional programmable electronic controller. Accordingly,these details of the density meter controller 7016-2 will not bedescribed in further detail for the sake of brevity.

FIGS. 2-11 show a density measurement device 7010 having an oscillatortube according to a first embodiment. Density measurement device 7010further includes a base 7014, a plurality of spacers 7015, a tubemounting block 7017, a flow connection manifold 7018, at least one or apair of permanent magnets 7025, an electronic circuit control board 7016and an electrical-communication interface unit 7016-1 configured forboth electrical power supply for the board and communication interfaceto system controller 2820. Base 7014 is configured for mounting thedensity measurement device on a flat horizontal support surface,vertical support surface, or support surface disposed at any angletherebetween. Accordingly, any suitable corresponding mountingorientation of the base may be used as desired. The mounting orientationof the base may be determined by the intended direction of oscillationof the oscillator tube 7011 taking into account the force of gravity onthe slurry laden oscillator tube. It is generally advantageous to mountall slurry passages in the oscillator tube in a manner that achieves thehighest percent of horizontal passages as possible, so that any settlingof particulate occurs perpendicular to the flow passage rather thaninline with it. Base 7019 may substantially planar and rectangular inshape in one embodiment as shown; however, other polygonal andnon-polygonal shaped bases may be used. The base may optionally includea plurality of mounting holes 7019 to facilitate mounting the base tothe support surface with a variety of fasteners (not shown). Base 7019defines a longitudinal centerline CA of the density measurement device7010 which is aligned with the length of the oscillator tube 7011(parallel to the tube's parallel legs as shown). In other words, thelength of the oscillator tube extends along the centerline CA. In oneembodiment, centerline CA and the flow passages within oscillator tube7011 may be horizontal as shown so that any settling that occurs isperpendicular to the flow through the passage rather than in-line withthe flow. In other embodiments, at least a majority of the flow passagesinside the oscillator tube may be horizontal in orientation.

Spacers 7015 may be elongated in structure and space the control board7016 apart from the base 7014 so that the oscillator tube 7011 mayoccupy the space 7015-1 created therebetween. Any suitable number ofspacers may be used for this purpose. The space is preferably largeenough to provide clearance for accommodating the motion of theoscillator tube 7011 and other appurtenances such as the frequencydriver and pickup 7012, 7013. The planar control board 7016 maypreferably be oriented parallel to the base 7014 as shown.

The frequency driver 7012 and pickup 7013 may be rigidly mounted tocircuit board 7016 in one embodiment as variously shown in FIGS. 2-11 .In other possible embodiments as shown in FIGS. 12-15 , the driver andpickup may be rigidly mounted to separate vertical supports 7031attached to base 7014. In each case, the driver and pickup are mountingadjacent and proximate to permanent magnets 7025, but do not contact thepermanent magnets. Permanent magnets 7025 generate a static magneticfield (lines of magnetic flux) which interacts with the driver 7012 andpickup 7013 for exciting the oscillator tube 7011 and measuring itsvibrational frequency when excited.

Tube mounting block 7017 is configured for rigidly mounting oscillatortube 7011 thereto in a cantilevered manner. Oscillator tube 7011 may bea straight U-tube configuration in one embodiment as shown in which allportions lie in the same horizontal plane. The straight inlet endportion 7011-1 and straight outlet end portion 7011-2 of oscillator tube7011 are mounted to and rigidly supported by the block 7017 (see, e.g.FIG. 11 ) to allow the tube to oscillate analogously to a tuning forkwhen electronically/electromagnetically excited. The mounting block 7017includes a pair of through bores 7017-1 which receive the end portions7011-1, 7011-2 of the oscillator tube complete therethrough. Bores7017-1 may be parallel in one embodiment. The U-bend portion 7011-3 ofthe oscillator tube opposite the inlet and outlet end portions andadjoining tube portions between the U-bend and mounting block 7017 areunsupported and able to freely oscillate in response to the excitationfrequency delivered by the driver 7012.

The inlet end portion 7011-1 and outlet end portion 7011-2 of oscillatortube 7011 project through and beyond the tube mounting block 7017, andare each received in a corresponding open through bore or hole 7018-1 ofthe flow connection manifold 7018 associated with defining a slurryinlet 7020 and slurry outlet 7021 of the connection manifold 7018 (seeslurry directional flow arrows in FIG. 11 ). Through holes 7018-1 mayhave any suitable configuration to hold the end portions 7011-1, 7011-2of oscillator tube 7011 in tight and a fluidly sealed manner. Suitablefluid seals such as O-rings, elastomeric sealants, or similar may beused to achieve a leak-tight coupling between the oscillator tube andconnection manifold 7018. The connection manifold 7018 abuttinglyengages the mounting block 7017 to provide contiguous coupling openingstherethrough for the inlet end portion 7011-1 and outlet end portion7011-2 to fully support the end portions of oscillator tube 7011 (see,e.g. FIG. 11 ). In other possible embodiment contemplated, theconnection manifold 7018 may be spaced apart from but preferably inrelative close proximity to mounting block 7017.

The mounting block 7017, flow connection manifold 7018, and base 7014may preferably made of a suitable metal (e.g. aluminum, steel, etc.) ofsufficient weight and thickness to act as vibration dampeners such thatexcitation of oscillator tube which is measured by the densitymeasurement device 7010 is indicative of only the frequency response ofthe filled oscillator tube 7011 without interference by anycorresponding parasitic resonances that otherwise could be induced inthe base or the mounting block and flow connection manifold.

In the first oscillator tube embodiment shown in FIGS. 2-11 , theoscillator tube 7011 may have a conventional U-shape as shown andpreviously described herein. The tube may be oriented parallel to theplanar top surface of the base 7014. Oscillator tube 7001 may be formedof a non-metallic material in one non-limiting embodiment. Suitablematerials include glass such as borosilicate glass. In other possibleembodiments, however, metallic tubes may be used. The permanent magnets7025 are fixedly and rigidly supported from and mounted to theoscillator tube 7011, such as on opposite lateral sides of the U-tubeproximate to the U-bend portion 7011-3 as shown. The U-bend portion isfarthest from the cantilevered portion of the oscillator tube adjoiningthe mounting block 7017 and thus experiences the greatestdisplacement/deflection when excited by driver 7012 making the tubevibration frequency change readily detectible by the digital metercontroller 7016-2. This creates the greatest sensitivity for frequencydeviation measurement of the slurry-filled oscillator tube 7011 versusthe natural frequency of the tube when empty; the deviation or differentin frequency being used by controller 7016-2 to measure the slurrydensity.

Although laboratory digital density meters having oscillator tubes arecommercially available, they are not entirely compatible off the shelffor measuring soil slurries or other agricultural materials that canhave a presence of varying amounts of iron (Fe) in the soil unlike otherfluids. The iron in the soil slurry creates a problem which interfereswith accurate soil slurry density measurement since iron particles inthe slurry are attracted to the permanent magnets used in the densitymeasurement device 7010. This causes the iron particles to aggregate onportions of the tube closest to the permanent magnets, thereby skewingthe density measurement results by adversely affecting the resonantfrequency of the oscillator tube when loaded with the soil slurry andexcited by driver 7012. FIG. 16A shows this undesirable situation withagglomerated Fe particle in the oscillator tube.

To combat the foregoing problem when handling iron particle-containingslurries, embodiments of a density measurement device 7010 according tothe present disclosure may be modified to include a variety of magneticisolation features or members configured to magnetically isolate thepermanent magnets from the oscillator tube 7011 and iron-containingslurry therein. In the embodiment of FIGS. 2-11 , the permanent magnets7025 may each be mounted to the oscillator tube 7011 by a magneticisolation member comprising a non-magnetic standoff 7024 (alsoschematically shown in FIGS. 16B and 16C). The standoffs projecttransversely outwards from the lateral sides of oscillator tube inopposite directions and perpendicular to longitudinal centerline CA ofthe density measurement device 7010. Standoffs 7024 are configured withsuitable dimensions or lengths to space the permanent magnets far enoughaway from the oscillator tube 7011 to prevent creating a static magneticfield of sufficient strength within the tube to attract and aggregatethe iron particles in the soil slurry for the reasons discussed above.The magnetic field can be such that its strength is weakened to thepoint that allows particles to move under the force of the flow withoutdeposition on the inside of the oscillator tube. As illustrated in FIG.16B, the magnet flux lines (dashed) which circulate and flow from thenorth (N) pole of permanent magnet 7025 to the south (S) pole do notreach the oscillator tube 7011. The magnet standoffs 7024 avoid the ironagglomeration problem shown in FIG. 16A caused by direct mounting of thepermanent magnets 7025 to the oscillator tube 7011.

In one embodiment where the oscillator tube 7011 is formed of anon-metallic and non-magnetic material (e.g. glass or plastic), thestandoffs 7024 may be integrally formed as a monolithic unitarystructural part of the tube. In other embodiments, the standoffs towhich the permanent magnets are mounted may be separate discreteelements which are fixedly coupled to the oscillator tube 7011 such asvia adhesives, clips, or other suitable coupling mechanical methods.Where a metallic oscillator tube is provided, the standoffs 7024 areformed of a non-metallic material (e.g. plastic or glass) attached oradhered to the oscillator tube by a suitable means (e.g. adhesives,clips, brackets, etc.).

Other possible arrangements for mounting the permanent magnets 7025 tooscillator tube 7011 and magnetic isolation members may be used whichshield or guide the creating magnetic lines of flux generated by themagnets away from the tube. For example, FIG. 16D shows a permanentmagnet assembly comprising a magnetic isolation member comprisingmetallic magnetic shield member 7030 interspersed between the permanentmagnet and oscillator tube to direct the magazine flux lines (dashed)away from the oscillator tube. In the embodiment shown, the shieldmember 7030 is configured as a flat plate of metal. FIG. 16E shows aU-shaped or cup shaped shield member 7030 which performs similarly toFIG. 16D. Any suitable shape of metallic magnetic shield member may beused so long as the magazine flux lines are redirected to not reach andpenetrate the oscillator tube 7011.

FIG. 16F illustrates that the direction of the oscillator tube 7011excitement via placement of the frequency driver and pickup 7012, 7013could be in the stiffest direction (e.g. 1eft/right represented by thetube oscillation movement arrows) or in the least stiff and mostflexible direction (e.g. up/down) for a horizontally oriented tube. Thiswill affect the natural frequency of the oscillator tube significantly,which forms the baseline against which the excited tube full of slurryis compared to determine the slurry density (weight). The stifferside-to-side excitement/movement direction of the tube will have ahigher natural frequency, while the more flexible up and down directionwill have a lower natural frequency. Either orientation, or differentangular orientations of the oscillator tube may be used. It may furtherbe advantageous in some embodiments to have the tube significantlystiffer in the direction of gravity (i.e. vertically) than in theloading/excitement direction (i.e. horizontal represented by the tubeoscillation movement arrows) as shown in FIG. 16B to help reduce systemnoise which could interfere with density measurement accuracy.

The density measurement device 7010 operates to obtain densitymeasurements from the soil slurry in a conventional manner known in theart for such U-tube type density meters. The slurry density measurementsare communicated to control system 2800 (programmable controller 2820)operably coupled to the density measurement device 7010 as seen in FIGS.1A-B. The measurements are utilized by the controller to automaticallydetermine how much water (diluent) needs to be added to the slurry toreach a preprogrammed target water to soil or other agricultural samplematerial ratio depending on the type of material to be sampled andanalyzed.

An exemplary method/process for preparing an agricultural sample slurryusing slurry density measurement with density measurement device 7010(density meter) and a preprogrammed closed loop control schemeimplemented by controller 2820 of the control system 2800 via suitableprogramming instructions/control logic will now be described. Thisexample will use soil as the sample for convenience of description, butis not limited thereto and may be used for other agricultural samplematerials (e.g. plants, manure, etc.). Given an arbitrary amount of soilin the collected sample with an associated arbitrary soil moisturecontent based on ambient conditions in the agricultural field and soiltype, the soil slurry will be diluted to reach a desired target densityreading thereby ensuring repeatable analytical results. Because not allsoil samples are made up of particles of the same density depending onthe nature of soil (i.e. sandy, clay, loam, etc.), the system willlikely have a varying desired density target based on these and othercharacteristics of the sample being analyzed. The target is a constantsoil mass to water mass ratio, which is represented by a target density.

FIGS. 28-30 are curves showing dilution amount of diluent (e.g. water)added to the slurry versus slurry density which is used by controller2820 to determine the amount of diluent required to reach thepreprogrammed target water to soil ratio. The target water to soil ratiocan be preprogrammed into the controller in the form of a target slurrydensity which can be directly equated to the ratio because the densityof the diluent used is a known fixed factor. With the known density ofthe diluent being used (e.g. water having a density of 0.998 g/mL) alsopreprogrammed into the controller, as more and more diluent is added tothe slurry in the system, the slurry mixture will ultimately approachthe density of the diluent but can never be reversed and become lessdense than this value. The relationship and curve shown in FIG. 28 isthus generated by the controller 2820 and used to reach the targetslurry density (water to soil ratio). The dilution amount (Y-axis) isthe total volume added to achieve the dilution. With different amountsof soil, soil moisture, and water (diluent) added to create the initialslurry mix, the slope of this curve may change but will keep the samegeneral shape.

With additional reference to FIGS. 1A-B, the collected raw soil sampleand a known amount of water are initially mixed in mixer-filterapparatus 100 a first time as indicated to prepare the slurry. Once thesoil slurry has been mixed and homogenized in the mixer, a first densitymeasurement is be sensed by the density meter and transmitted tocontroller 2820. Point 7090A on the curve in FIG. 28 indicates the firstdensity measurement taken.

To determine the dilution amount versus slurry density relationship moreprecisely in real-time, a known amount of water is metered and added bycontroller 2820 via operably coupled water control valve 7091 tomixer-filter apparatus 100 in the next step (e.g. 20 mL) and theresultant slurry density is measured a second time. Point 7090B on thecurve in FIG. 29 indicates the second measurement taken. A linearrelationship can then be generated by the controller between the twoslurry density points 7090A and 7090B taken (represented by solid lineon the curve between these two points). For a given preprogrammed targetslurry density (soil to water ratio), the target density can then beinput to this relationship and the output calculated by controller 2820is a first estimation of the total amount of diluent (e.g. water) neededto achieve the target density.

The controller 2820 next meters and adds the estimated amount ofadditional diluent necessary to reach the target slurry density to theslurry mixture which is mixed with the slurry by mixer-filter apparatus100. The resultant slurry density is measured a third time. Point 7090Con the curve in FIG. 30 indicates the third measurement taken, whichcontinues to add data points to the linear relationship (see longersolid line on curve). Once at least three slurry density measurementsand corresponding points on the slurry density curve have been acquiredby the controller, a polynomial regression can be performed on the databy the controller providing a more precise curve fit. Based on and usingthe preprogrammed target density, the controller 2820 then calculatesthe required total amount of diluent necessary based on the updatedcurves and adds this amount to the slurry to achieve the target slurrydensity. This process can be iterated to improve the accuracy of theregression model or until the actual density is sufficiently close tothe target density

FIGS. 12-15 depict an alternative second embodiment of a cantileveredU-shaped oscillator tube 7032 for use with density measurement device7010 which contrasts to the straight U-shaped oscillator tube 7011previously described herein. In this present embodiment, oscillator tube7032 has a recurvant U-tube shape in which the 180 degree primary U-bendportion 7032-3 extends backwards over top of the straight inlet endportion 7032-1 and outlet end portion 7032-2 of the oscillator tubeaffixed to tube mounting block 7017 and flow connection manifold 7018.This is created by the addition of two additional 180 degree secondaryU-bend portions 7032-4 between the straight end portions 7032-1, 7032-2and the primary U-bend portion 7032-3. One secondary U-bend portion7032-4 is disposed in the slurry inlet leg of the oscillator tubeupstream of primary U-bend 7032-3, and the other in the slurry outletleg of oscillator tube downstream of the primary U-bend portion asshown. In this recurvant oscillator tube embodiment, the standoffs 7024are disposed on the secondary U-bend portions and protrude laterallyoutwards in opposite lateral directions to hold the permanent magnets7025 in spaced part relation to the oscillator tube. The frequencydriver and pickup 7012, 7013 are supported from base 7014 by separatevertical supports 7031 in proximity to the permanent magnets to excitethe oscillator tube 7032 as previously described herein.

In recurvant oscillator tube 7032, slurry flow follows the pathindicated by the directional flow arrows in FIG. 14 . Slurry flow movesin a first direction parallel to centerline axis CA twice, and in anopposite direction parallel to centerline axis CA twice as well byvirtual of the primary and secondary U-bend portions 7032-3 and 7032-4.Primary U-bend portion 7032-3 is oriented horizontal while second U-bendportions 7032-4 are oriented vertically. In this design, centerline CAand a majority of the flow passages within oscillator tube 7011 mayremain horizontal in orientation as shown so that any settling thatoccurs is perpendicular to the flow through the passage rather thanin-line with the flow.

In contrast to the first U-shaped oscillator tube 7011 of FIG. 2 firstdescribed above, the triple bend recurvant oscillator tube 7032 designis advantageous because the vibration displacement is mirrored betweenthe left and right sides of the tube (i.e. vertical bends 7032-4 bendsmove towards each other, then away from each other as the tubeoscillates). Due to this, there are always equal and opposite forcescanceling each other out during oscillation, and thus the vibration isnot affected by external influences on mass, stiffness, or damping ofthe base and other components. The previous straight U-tube oscillatordesign would propagate vibration into the base easily as the oscillationwas not counterweighted, and thus the entire system vibrates somewhat.Since the entire system vibrates, any external influences on the entiresystems mass, stiffness, or damping would artificially change thenatural frequency, thereby adversely affecting accuracy to some degree.The straight U-tube oscillator nonetheless may be acceptable insituations not subjected to undue external influences.

The remainder of the density measurement device 7010 setup andcomponents are essentially the same as the embodiment utilizingoscillator tube 7011 and will not be repeated here for the sake ofbrevity.

In some embodiments, a single device which combines the foregoingfunctions of both frequency transmitter or driver 7012 and receiver orpickup 7013 may be provided in lieu of separate units. Such a device maybe an ultrasonic transducer as one non-limiting example. For a combinedsingle driver-pickup device 7012/7013, the device could be activated toexcited the oscillator tube 7011, stopped for a few oscillations of theoscillator tube, and then reactivated to measure the resultantoscillation frequency response of the tube. In the combined design, onlya single permanent magnet 7025 is required located proximate to thedriver/pickup.

Fine Filtration Filter

The filter unit of the fine filtration sub-system 7003 shown in FIGS. 1Aand 1B will now be further described. In testing, the inventors havediscovered that “fine” filtering (e.g. 0.010 inches/0.254 mm) directlyout of the mixer-filter apparatus can in some situations adversely andsignificantly affect the ability to obtain a consistent water to soilratio (e.g. 3:1) across all types of soils which might be encountered,sampled, and tested. Accordingly, it is beneficial to understand andmeasure the density of the mixed raw soil sample slurry from themixer-filter apparatus 100 before performing fine filtering.Accordingly, preferred but non-limiting embodiments of the disclosedagricultural sample analysis systems 7000 comprise both a coarse filter146 upstream of density measurement device 7010, and a fine filter 7050or 7060 downstream of the density measurement device; each of which isdescribed in greater detail below. Two different exemplaryconfigurations of the agricultural sample analysis system comprisingthis two-stage slurry filtering are disclosed; one with slurryrecirculation from the fine filter unit back to the mixer-filterapparatus 100 shown in FIG. 1B and one without recirculation shown inFIG. 1A further discussed herein.

The agricultural sample analysis system utilizes a first coarse filter146 having a very coarse screen (e.g. about 0.04-0.08 inch/1-2 mmmaximum particle size passage in one possible implementation) toinitially screen and filter out larger size stones, rocks and aggregatefrom the slurry to avoid clogging/plugging of the flow conduit (tubing)lines upstream of microfluidic processing disk 310 while stillpermitting an accurate density measurement in density measurement device7010. Coarse filter 146 may be incorporated into mixer-filter apparatus100 in one embodiment as previously described herein, or may be aseparate downstream unit. This coarse filtering is followed by finefiltering in fine filter units 7050 or 7060 having fine screening (e.g.1ess than 0.04 inch/1 mm, such as about 0.010 inch/0.25 mm maximumparticle size passage in one possible implementation) to allow theagricultural slurry sample to pass through the microfluidic flow networkand components of the analysis processing wedges 312 of microfluidicprocessing disk 310 shown in FIGS. P-96 to P-121 without causing flowobstructions/plugging. For soil, these extremely small particles passedby the fine filter unit make up the vast majority of the nutrientcontent of the soil, so it is acceptable to use finely filtered slurryfor the ultimate chemical analysis in the system. It bears noting thatthe fine filtering step and filter units 7050, 7060 are useable andapplicable to slurries comprised of other agricultural materials to besampled (e.g. vegetation, manure, etc.) and thus not limited to soilslurries alone.

FIGS. 17-21 show a first embodiment of a fine filter unit 7050 useablewith either of the soil slurry preparation and analysis systems shown inFIGS. 1A-B. Fine filter unit 7050 is configured for particular use withthe slurry recirculation setup of FIG. 1B which includes a closedrecirculation flow loop 7059 between the fine filter unit 7050 (or 7060)and mixer-filter apparatus 100 as shown.

Filter unit 7050 comprises a longitudinal axis LA, pre-filtered slurryinlet nozzle 7051, pre-filtered slurry outlet nozzle 7052, pluralfiltrate outlets 7053 (post-filtered), internal pre-filtered slurrychamber 7057, internal filtrate chamber 7054, and one or more filtermembers such as screens 7055 arranged between the chambers. Screens 7055may be arcuately shaped in one embodiment and positioned at the top ofthe slurry chamber 7057 as best shown in FIG. 21 . Any number of screensmay be provided. A pair of annular seals 7056 fluidly seals the inletand outlet nozzles 7051, 7052 to the main body of the filter unit toallow initial placement of the filter screen 7055 inside the filter unitbefore securing the inlet and outlet nozzles to the body. The main bodymay be block-shaped, cylindrical, or another shape. The nozzles may beuncoupled from the central main filter body in order to access theinterior of the filter unit and initially install or periodicallyreplace the screens. Threaded fasteners 7058 or other suitable couplingmeans may be used to couple the inlet and outlet nozzles to the opposingends of the main body. The slurry inlet and outlet nozzles 7051, 7052may have any suitable configuration in order to accept any suitable typeof tubing connector to fluidly couple the system slurry tubing 7088 tothe filter 7050. One non-limiting example of tubing connector that couldbe used is John Guest plastic half cartridge connector which iscommercially-available. Other tubing connectors may be used. Anysuitable non-metallic (e.g. plastic) or metallic materials may be usedto construct filter unit 7050 including screens 7055. In one embodiment,the main body of the filter unit may be plastic and the screens 7055 maybe metallic such as gridded mesh defining mesh openings.

In operation and describing the slurry flow path through fine filterunit 7050 with respect to FIG. 1B, unfiltered slurry flows in sequence(upstream to downstream) from the coarse filter 146 through densitymeasurement device 7010 and enters the fine filter unit through theinlet nozzle 7051. The slurry flows axially and linearly throughpre-filtered slurry chamber 7057, and then exits the filter throughoutlet nozzle 7052 back to mixer-filter apparatus 100 (see, e.g. “sampleprep. chamber” in FIG. 1B). A slurry recirculation pump 7080 may beprovided to fluidly drive the recirculation flow in the closedrecirculation flow loop 7059 and return the yet to be fine filteredslurry back to the mixer-filter apparatus. Any suitable type of slurrypump may be used. The recirculation pump may be omitted in someembodiments if the main slurry pump 7081 provides sufficient fluid powerto drive the slurry flow through the entire closed recirculation flowloop 7059. The system continuously recirculates the coarsely filteredslurry back into the main blending chamber of the mixer for a period oftime. This recirculation can advantageously help with getting ahomogeneous slurry mixture more quickly for analysis than with the mixeralone by continuously recycling the slurry through the mixer and coarsefilter in the closed recirculation flow loop 7059. During densitymeasurement, water is automatically metered and added to themixer-filter apparatus 100 by the previously described control system2800 (including programmable controller 2820) based on the systemmonitoring the slurry density measured by density measurement device7010, which is operably coupled to the controller in order to achievethe preprogrammed water to soil ratio. The slurry is better mixed bythis continuous slurry recirculation.

Once a coarsely filtered homogeneous slurry having the desired water tosoil ratio is achieved, a small minority portion of the recirculatingslurry stream may be bypassed and extracted from fine filter unit 7050for initial processing in analyte extraction sub-system 7004 andsubsequent chemical analysis (see, e.g. FIG. 1B). The extracted slurryflows transversely through filter screens 7055 and into filtrate chamber7054, and then outwards through the filtrate outlets 7053 to the analyteextraction sub-system. The flow of extracted slurry may be controlled bysuitable control valves 7070 changeable in position between open fullflow, closed no flow, and throttled partially open flows therebetween ifneeded. Valves 7070 may be manually operated or automatically operatedby controller 2820 to open at an appropriate time once homogenous slurryhaving the desired water to soil ratio has been achieved, or asotherwise preprogrammed. Additional valves may also be used to open flowto water in order to backflush the filter during the cleaning cycle inpreparation for the next sample.

Although two filtrate outlets 7053 are shown in FIGS. 17-21 , otherembodiments may have more than two filtrate outlets or less (i.e. oneoutlet). Each filtrate outlet 7053 is fluidly coupled to and suppliesfine filtered slurry (filtrate) to a separate one of the dedicated soilsample slurry processing and analysis trains or systems previouslydescribed herein (e.g. analysis processing wedges 312 shown in FIGS.P-96 to P-121 or another); each train fluidly isolated from others andconfigured for quantifying the concentration of a different analyte ofinterest (e.g. plant nutrients such as nitrogen, phosphorus, potassium,etc.) in parallel.

It bears noting that the term “pre-filtered” used above only refers tothe fact that the soil slurry has not been filtered yet with respect tothe fine filter unit 7050 being presently described. However, the slurrymay have undergone previous filtering or screen upstream however such asin coarse filter 146 seen in FIGS. 1A-B. Accordingly, the slurry may befiltered before reaching fine filter unit 7050 downstream.

Fine filter unit 7050 is configured to eliminate the passage of soil orother particles in the slurry which cause blockages in or otherwiseobstruct the extremely small diameter microfluidic flowpassages/conduits and microfluidic processing disk flow components suchas valves, pumps, and chambers formed within the analysis processingwedges 312 of microfluidic processing disk 310 shown in FIGS. P-96 toP-121 and previously described herein. Accordingly, filter screens 7055of fine filter unit 7050 are sized to pass soil particles compatiblewith the microfluidic processing disk and smaller in size than thosescreened out by the upstream coarse filter 146 associated with themixer-filter apparatus. The filter screens 7055 have a plurality ofopenings each configured to remove particles greater than apredetermined size from the slurry to yield the filtrate. Screens 7055may be formed of a grid-like metallic mesh in one embodiment whichdefines the mesh openings for filtering the slurry.

Accordingly in one preferred embodiment, the first coarse filter 146 ofthe system is configured to pass slurry having a first maximum particlesize, and the second fine filter unit 7050 is configured to pass slurryhaving a second maximum particle size smaller than the first maximumparticle size. Furthermore, the ultrafine filtration sub-system 7005which comprises the third ultrafine filter 5757 (which may beincorporated into or associated with microfluidic processing disk 310 orassociated with soil sampling system 3000) is configured to pass slurryhaving a third maximum size smaller than the first and second maximumparticle sizes. As previously described herein, the ultrafine filter5757 is micro-porous filter which can replace the centrifuge 331 and isconfigured to produce the clear filtrate from the soil slurry andextractant mixture which serves as the supernatant for chemicalanalysis. Accordingly, the performance of ultrafine filter 575 surpassesboth the coarse and fine filters in terms of the smallest maximumpassable particle size. As a non-limiting example, representative poresizes that may be used for ultrafine filter 575 is about and including0.05 μm to 1.00 μm. It bears noting that the foregoing terms “first,”“second,”, and “third” are used to connote the filter units which theslurry encounters in sequence flowing from upstream to downstream whenpassing through the systems shown in FIGS. 1A-B. Accordingly, themaximum slurry particle size continuously gets smaller as the slurrypasses through each filter unit in sequence.

In an ordinary filter operation, all flow is directed through the screenand anything that does not pass through the screen stops on the screenand builds up. This requires the screen to be either drained orback-flushed after a period of time to keep it clean and functional forits purpose. If a lot of particulate material needs to be filtered out,this may lead to a very short time period for which the filter will workproperly before needing cleaning. For this reason, the new screen finefilter units 7050, 7060 were designed which operate on the principle ofextracting only a small amount soil slurry for testing from the mainslurry recirculation flow path as described above instead ofintercepting all of the slurry flow for fine filtering. Doing thisadvantageously enables the filter to stay clean for a much longer periodof time because only a minority portion of the slurry flow is extractedand travels through the screen transversely to the main direction of theslurry flow through the filter unit. In addition, the main slurry flowpath which preferably is oriented parallel to the plane occupied by thescreen 7055 continually scrubs and cleans the filter screens 7055 (see,e.g. FIGS. 20-21 ) by shearing action of the flow to preventaccumulation of particles on the screens. It further bears noting thatthe fine filter units 7050 and 7060 advantageously avoids internal areasthat have low pressure or flow where particulates can accumulate. It isalso desirable to avoid internal surface orientations in the filter inwhich particulates will accumulate due to gravity. Accordingly,embodiments of fine filter units 7050, 7060 preferably may be orientedsuch that the filter screens 7055, 7065 respectively are above the mainflow and juncture where the bypass slurry flow is drawn off for chemicalanalysis and preferably in a transverse direction to the main flow pathof slurry through the filter bodies (see, e.g. FIGS. 21 and P-238).

FIGS. 22-26 shows the second embodiment of a fine filter unit 7060 notedabove. Fine filter unit 7060 comprises a plurality of optionallyreplaceable filter screen assemblies or units 7068. In this embodimentby contrast to fine filter unit 7050, the filter screen units can beremoved and replaced without breaking the end fluid connections to thesystem tubing/piping, thereby greatly facilitating periodic changeout ofthe screens over time. Filter unit 7050 has internally mounted screens7055, which can be accessed by removing the slurry inlet and outletsnozzles 7051, 7052 as previously described herein. In some embodiments,filter screen units 7068 may be constructed to be disposable such that anew screen unit is interchanged with the used plugged screen units whenneeded.

Fine filter unit 7060 has an axially elongated main body which defines alongitudinal axis LA, a pre-filtered slurry inlet 7061, pre-filteredslurry recirculation outlet 7062, plural filtrate outlets 7063(post-filtered), internal pre-filtered main slurry chamber 7067 in fluidcommunication with the inlet and outlet, and plurality of filter screenunits 7068 each comprising a filter member such as screen 7065 arrangedbetween the chamber 7067 and one filtrate outlet 7063. Inlet 7061 andoutlet 7062 may preferably be located at opposite ends of the finefilter unit body at each end of chamber 7067, thereby allowing the mainslurry chamber to define a slurry distribution manifold in fluidcommunication with each filtrate outlet 7063. Screens 7065 may beconvexly curved and dome shaped in some embodiments (best shown in FIG.26 ). The main slurry chamber 7067 extends axially between the inlet andoutlets 7061, 7062 beneath the screen units 7068. Fine filter unit 7060,albeit convexly shaped, may be used in the orientation shown such thatportions of the screens 7065 exposed to the slurry in main slurrychamber 7067 may be considered substantially horizontally oriented andparallel to longitudinal axis LA and the axial flow of slurry throughthe main slurry chamber screens. Flow through the screens is further inan upward direction (transverse to longitudinal axis LA and the axialslurry flow in the chamber) when the fine filter unit 7060 is used inthe preferred horizontal position. This combines to advantageously both:(1) scrub and clean the screens 7065 as the slurry flows past thescreens in the slurry chamber 7067 thereby preventing accumulation ofslurry particles on the screens until the filtrate is extracted, and (2)counteracts the affects of gravity for accumulating particulate on thescreens since the slurry enters the screens from the bottom therebykeeping the particles below the screens until filtrate extractionoccurs.

Fine filter unit 7060 is axially elongated such that the screen units7068 may be arranged in a single longitudinal array or row as shown sothat the main slurry chamber 7067 is linearly straight to avoid creationof internal dead flow and lower pressure areas in the slurry flow pathwhere particulate in the slurry might accumulate.

An annular seal 7066 which may be elastomeric washers in one embodimentmay be incorporated directly into each filter screen unit 7068 as partof the assembly to fluidly seal the screen unit to the main body of thefilter unit. Screen unit 7068 may have a cup-shaped configuration in oneembodiment (best shown in FIG. 26 ) with the convexly curved dome-shapedscreen 7065 protruding outwards/downwards from one side of the seal 7066into the main slurry chamber 7067. Each screen unit 7068 is received ina complementary configured upwardly open receptacle 7069 formed in themain body of the filter unit 7060 which fluidly communicates with themain slurry chamber 7067 of the filter unit. A screen retainer 7064 maybe detachably coupled to the filter unit main body and received at leastpartially in each receptacle to retain each screen unit as best shown inFIG. 26 . The main body may be block-shaped, cylindrical, or anothershape. The filtrate outlets 7063 may an integral unitary structuralportion of the screen retainers 7064 in one embodiment, and can beterminated with a conventional tubing barb in some embodiments as shownto facilitate coupling to the flow conduit tubing of the system. Othertype fluid end connections may be used. Filtrate outlets 7063 extendcompletely through the retainers from top to bottom (segment. FIG. 26 ).Retainers 7064 may have a generally stepped-shape cylindricalconfiguration in some embodiments. Threaded fasteners 7058 or othersuitable coupling means may be used to removably couple the retainers7064 to the main body of the filter unit. The retainers 7064 trap thefilter screen units 7068 in the receptacles 7069. Any suitablenon-metallic (e.g. plastic) or metallic materials may be used toconstruct filter unit 7060 including screens 7065. In one embodiment,the main body of the filter unit may be plastic and screens 7065 may bemetallic.

Similarly to filter unit 7050 and screens 7055, the screen units 7068have screens 7065 each configured to remove particles greater than apredetermined size from the slurry to produce the filtrate. The filterscreens 7065 thus have a plurality of openings each configured to passslurry having a predetermined maximum particle size. Screens 7065 may beformed of a grid-like metallic mesh in one embodiment which defines themesh openings for filtering the slurry. Other embodiments of screens7065 or 7055 may use polymeric meshes. Other type filter media may beused in other possible embodiments to perform the desired slurryscreening.

An exemplary process for exchanging filter screen units 7068 includesremoving the threaded fasteners 7058, withdrawing the retainers 7064from each receptacle 7069 transversely to the longitudinal axis LA ofthe filter unit main body, withdrawing the filter screen unitstransversely, inserting new screen units transversely to thelongitudinal axis LA into each receptacle, re-inserting the retainersinto the receptacles, and reinstalling the fasteners.

An overview of one non-limiting method for preparing an agriculturalsample slurry using the slurry recirculation and dual filteringgenerally comprises steps of: mixing an agricultural sample with waterin a mixing device to prepare a slurry; filtering the slurry a firsttime; measuring a density of the slurry; recirculating the slurry backto the mixing device; and extracting a portion of the recirculatingslurry through a secondary fine filter to obtain a final filtrate.Filtering the slurry the first time passes slurry comprising particleshaving a first maximum particle size, and filtering the slurry thesecond time passes slurry comprising particles having a second maximumparticle size smaller than the first maximum particle size. The finalfiltrate then flows to any of the agricultural sample analysis systemsdiscloses herein which are configured to further process and measure ananalyte in the slurry.

It bears noting that both fine filter units 7050 and 7060 may be usedwith the agricultural sample analysis system of FIG. 1A without slurryrecirculation by simply closing the respective recirculation outletnozzles via a plug or a closed valve fluidly coupled to the outletnozzle. Alternatively, the slurry could flow to waste after passingthrough the fine filter. In this case, the filtrate would need to beextracted from the slurry while it is flowing through the filter.

In lieu of the pump recirculation system of FIG. 1B, FIG. 27 is aschematic diagonal showing an alternative equipment layout and methodfor recirculating the coarsely filtered slurry through fine filter units7050 or 7060 using pressurized air instead. Two blending chambers arefluidly coupled to the inlet and outlet of a fine filter unit 7050 or7060 as shown by the flow conduit network layout which may be piping ortubing 7086 shown. At least one of the blending chambers may be providedby mixer-filter apparatus 100A for initially preparing the water andsoil slurry. The other blending chamber may be an additionalmixer-filter apparatus 100B, or alternatively simply an empty pressurevessel. Four slurry valves 7085A, 7085B, 7085C, and 7085D are fluidlyarranged between the fine filter unit and each of the chambers as shownfor controlling the direct of the slurry during blending. In operation,if the slurry is first prepared in mixer-filter apparatus 100A (sampleprep. chamber #1), valves 7085B and 7085C are opened, and valves 7085Aand 7085D are closed. Mixer-filter apparatus 100A is pressurized withair from valved pressurized air source 7086 which causes the slurry toflow through density measurement device 7010 and the fine filter unit7050 or 7060 to mixer-filter apparatus 100B. Valves 7085B and 7085C arethen closed, and valves 7085A and 7085D are opened. Mixer-filterapparatus 100B is then pressurized causing the slurry to flow in areverse direction through fine filter unit 7050 or 7060 and densitymeasurement device 7010 back to mixer-filter apparatus 100A. Thesequence cycle is repeated multiple times to continue the slurryblending. The valving and pressurized air sources may be operablycoupled to and controlled by system controller 2820 pressure, which maybe programmed to cause this back and forth flow to occur very rapidly.The slurry density may be measured continuously each time the slurryflows through the density meter. Once the slurry is thoroughly blendedas desired, the filtrate outlets from the fine filter units are openedto direct the filtered slurry to the extraction sub-system 7004 shown inFIG. 1B for processing and chemical analysis. In some embodiments, asingle pressurized air source may be used for each mixing chamber inlieu of separate sources. In another embodiment, the second chambercould be mounted directly above the first sample preparation chamberwith a valve between. Instead of pressurizing the second chamber,gravity would allow the slurry to flow back down into the first chamber.

System Slurry Flow Conduit Sizing

The internal diameter (ID) of the slurry flow conduit such as slurrytubing 7088 shown in FIGS. 1A-B is critical to proper operation of theagricultural sample analysis systems 7000 without plugging the tubing.When moving slurry with large particles through a small tube, thelikelihood of clogging increases. For nearly laminar flow, the velocityat the wall is near zero which may exacerbate clogging. For smalltubing, this becomes significant because of high frictional forces onthe slurry. If these frictional forces become too significant, particlesfall out of the flow and build up in the tubing causing a flow stoppage.Additionally, large particles can wedge with other large particles in asmall tube and cause blockages and flow stoppage. However, having verylarge tubing is problematic because it is difficult to have sufficientflow to keep particles in suspension to prevent soil particleprecipitates.

The inventors have discovered that the internal diameter of the slurrytubing 7088 and passages should be designed in such a way that theinternal cross sectional diameter is at a minimum two times the largestparticle size in the slurry. That is, as an example, if the particlesare screened to 2 mm in size (e.g. diameter) by the coarse filter 146 orfine filter units 7050 or 7060, the ID of the tubing should be no lessthan 4 mm diameter. Conversely, the internal diameter of tubing andpassages should be designed in such a way that the cross sectionalinternal diameter is at most ten times the largest particle size (e.g.diameter). That is, as an example, if the particles are screened to 2 mmin size, the ID of the tubing should be no greater than 20 mm indiameter. Accordingly, the preferred internal diameter of the slurrytubing 7088 has a critical range between at least two times the largestparticle size/diameter and no greater than ten times the largestparticle size/diameter.

In some embodiments, the tubing material used may preferably be flexibleand formed of a fluoropolymer, such as without limitation FEP(fluorinated ethylene propylene) in one non-limiting example. Otherfluoropolymers such as PTFE (polytetrafluoroethylene), ETFE(polyethylenetetrafluoroethylene), and PFA (perfluoroalkoxy polymerresin). The dynamic coefficient of friction (DCOF) associated with thesefluoropolymers also affects the preferred range of tubing internaldiameter discussed above because the tubing material creates frictionalresistance to slurry flow. FEP, PTFE, ETFE, and PFA each have a DCOFfalling the range between about and including 0.02-0.4 as measured perASTM D1894 test protocol. Accordingly, the tubing material used forslurry tubing 7088 associated with the above critical tubing internaldiameter range preferably also has a DCOF in the range between about andincluding 0.02-0.4, and more particularly 0.08-0.3 associated with FEPin some embodiments. Testing performed by the inventors confirmed thatuse of FEP tubing falling within the critical internal tubing diameterrange avoided the slurry flow blockage issues noted above. In otherpossible embodiments, nylon or other type tubing material may be used.

Multiplexed Pneumatic Control System with Pressure-Amplified Control AirValves

FIGS. 38-40 show a non-limiting embodiment of a pressure-amplifiedelectro-pneumatic control air valve 7600. This valve allows multiplexingwith a single electro-pneumatic actuated valve that is shared betweensimilar functions of multiple analyses which can be conductedsimultaneously by the slurry processing/analysis systems disclosedherein. As a non-limiting example, when multiple analyses are conductedfor different analytes in different slurry processing trains or slurryanalysis processing wedges 312 in parallel, each for example using theirown associated slurry filter(s) or other flow components in which theslurry or water fluid flow through the component must be controlled(e.g. flow on/flow off), one common pressure pneumatic air signal can besent to as many filters or flow components as necessary from upstreamcontrol air valve 7600 so they all actuate each separate functionsimultaneously. This advantageously avoids the requirement for multiplemore costly electro-pneumatic valves for every single function for eachslurry filter or other flow component. Fluid flow for each filter orflow component individual function in the complete slurry processingsystem may then be controlled by far less expensive air-piloted valvewhich received the pressure signal from control air valve 7600. Such asystem arrangement is described further below in more detail.

With continuing reference to FIGS. 38-40 , pressure-amplifiedelectro-pneumatic control air valve 7600 may be a poppet valve in oneembodiment as shown. Valve 7600 generally includes valve body 7604, airinlet 7601, fluid inlet 7602 communicating with a fluid inlet passageway7610, fluid outlet 7603 communicating with fluid outlet passageway 7611,flexible air diaphragm 7608, flexible fluid diaphragm 7606, andmultiplier plunger 7607 arranged therebetween. Plunger 7607 is coupledto the diaphragms at each end. The plunger is slideably disposed incentral bore 7613 and may be arranged along and parallel to theactuating centerline CL of the valve. Fluid diaphragm 7606 is configuredto alternatingly seal the fluid inlet passageway 7610 at valve seatingsurface 7615 from the fluid outlet passageway 7611. Seating surface 7615is disposed in fluid chamber 7609 formed between the fluid inletpassageway and fluid diaphragm 7606. An air chamber 7608 is formed onthe air-side of air diaphragm 7608 which receives the control air signalfrom the air inlet passageway 7612 and air inlet 7601. Valve body 7604may be formed of any suitable non-metallic or metallic material. In oneembodiment, the valve body may be plastic. The diaphragms 7605 and 7606may be formed of any suitable elastomeric material. In some embodiments,as shown, the valve body 7604 may be formed of two or more removablycoupled body segments 7604-1, 7604-2, and 7604-3. This allows theinternal valve components such as the diaphragms and plunger to beeasily assembled. The valve body segments may be fastened together inany suitable manner, such as a threadable coupling via threadedfasteners (not shown—see fastener mounting holes at each corner of valvebody) as one non-limiting example. In other possible embodiments, thesegments may be permanently coupled together such as via suitableadhesives.

Control valve 7600 may further include an electronic valve actuator 7620which may be coupled directly to valve body 7604 in some embodiments forforming a compact valve unit. Actuator 7620 is activated and controlledvia an electronic control signal transmitted from system controller 2820(see, e.g. FIG. P-302 and prior description herein) operably coupled tothe actuator (see, e.g. FIG. 42 dashed communication links). Controlvalve 7600 is fluidly coupled to an upstream control air source 7701 anddownstream to operating valves of at least one filter such as ultrafinefilter 5757 or other flow component of the agricultural slurry analysissystem further described below.

Plunger 7607 is axially movable between an unactuated position withoutapplication of a control air signal to diaphragm 7608, and an actuatedposition with application of control air. In the actuated position, thefluid diaphragm 7606 engages valve seating surface 7615 to shut offfluid flow through the valve. This represents the closed position ofvalve 7600. In the unactuated position, the fluid diaphragm disengagesseating surface 7615 to allow flow through the valve as shown in FIG. 40. This represents the open position of the valve.

Pressure amplified pneumatically operated control air valves allows arelatively low pressure air signal to actuate the valve which iscontrolling and providing downstream pressures that are relatively high.Air diaphragm 7605 is larger in diameter D1 and surface area A1 thandiameter D2 and corresponding arear A2 of fluid diaphragm 7606. Fluidinlet passageway 7610 had a diameter D3 and corresponding area A3 at thepenetration through the valve seating surface 7615. In one non-limitingexample to illustrate the pressure amplification aspects of valve 7600,the air signal pressure P1×air diaphragm area A1=plunger force. Plungerforce/A2 is larger than the controlled fluid pressure P2, even when P2is greater than air signal pressure P1. Once the valve is closed, thevalve is capable of holding back fluid at upstream fluid inlet pressuresup to P1×A1/A3.

FIG. 42 an exemplary non-limiting embodiment of a multiplexed controlair system using the pressure-amplified electro-pneumatic control airvalves 7600 described above. The multiplexed control air system usesvalves 7600 for controlling the operation of multiple flow components indifferent slurry processing and analysis trains or processing wedges312, such as for example ultrafine filter units 7700. Ultrafine filterunits 770 are each configured and operable to produce a substantiallyclear filtrate which provides the supernatant for chemical analysis andquantification of a respective slurry analyte of interest in each trainor wedge (e.g. soil nutrient or other) after the extractant addition toseparate the analyte from the slurry, but before the reagent added forthe analysis. FIG. 43 is a transverse cross-sectional view of onenon-limiting exemplary construction of an ultrafine filter unit 7700which will be described first before description of the multiplexedcontrol air system.

Referring initially to FIG. 43 , ultrafine filter unit 7700 includes anelongated filter body 7704 defining a filter centerline axis CF andcomprising a first end such as top end 7715, an opposite second end suchas bottom end 7716, and an internal central passage 7712 extendingbetween the ends along centerline axis CF. Filter body 7704 may have agenerally cylindrical configuration in one embodiment; however, othershaped bodies may be used in other implementations. The filter body mayhave a monolithic unitary structure in one embodiment, which may be castor molded from any suitable chemically inert non-metallic or metallicmaterials which will not react with the slurry. In one embodiment, thefilter body may be formed of plastic/polymer.

A filter media holder 7720 is removably positioned and received incentral passage 7712 of filter body 7704. Filter media holder 7720 maybe elongated having a first end portion 7722 defining a first end andopposite second end portion 7723 defining a second end. The ends may beflanged in one embodiment as shown; however, the ends may not be flangedin other embodiments. Each end portion 7722, 7723 is configured to mountand support an axially elongated filter media 7721 therebetween. Filtermedia 7721 may have a tubular configuration defining an internalfiltrate chamber 7714 which receives filtered slurry (i.e. filtrate)passing radially inwards through the filter media from an annular slurryinlet plenum 7713 defined between the filter body and filter media. Anysuitable microporous media similar to that previously described hereinfor ultrafine filter 5757 may be used for ultrafine filter media 7721,such as for example without limitation microporous polymeric material,or sintered metal or ceramic. An “ultrafine” filter for producing afiltrate (or supernatant) of suitable maximum particle size for chemicalanalysis by the system may be defined in some non-limiting embodimentsas a filter media having a maximum particle size pass through in a rangefrom 0.1 to 10 microns.

Ultrafine filter unit 7700 in one embodiment comprises a plurality ofinlet and outlet ports, including but not limited to a slurry inlet port7705, filtrate outlet port 7710, waste outlet ports 7709, 7711,vent/overflow port 7708, filter pressurization air inlet port 7706, airport 7726 and filter backwash inlet port 7707. Air port 7726 may beconfigured as a two-way port to introduce pressurized air into thefilter unit and to vent air from the unit during the initial slurryfill, as further described herein. The air port 7726 and filtrate outletport 7710 may be orientated parallel to the filter centerline axis CFand filter media 7721. All other ports described above are orientedtransversely and tangentially to axis CF and the filter media to createa swirling/mixing action to occur in the annular slurry inlet plenum7713.

Each of the foregoing ports has an associated pneumatic air pilot valve7724 which is fluidly coupled on the process liquid or fluid side (e.g.slurry, water, air, etc.) to the ports to control the flow of the fluidto/from the ultrafine filter unit 7700. All valves shown in FIG. 43 areair pilot valves; only a few being labeled for sake of figure clarity.Each air pilot valve 7724 is fluidly coupled on the control air side inturn to a dedicated and associated control air valve 7600 as shown inFIG. 42 according to the type of port (e.g. water, air, slurry). Thecontrol air valve 7600 delivers pulse air to operate each air pilotedvalve 7724 to control its on or off position. In one embodiment, the airpiloted valves may be configured as air pressure to open, and air orspring to close via an included return spring (single pilot pneumaticvalve) or air pressure to close (double pilot pneumatic valve). Such airpilot valves are commercially available from numerous sources andrelatively inexpensive in contrast to pneumatic pressure-amplifiedcontrol air valve 7600 which requires an electrical signal to operatethe valve's electronic valve actuator 7620. It bears noting that for theultrafine filter unit 7700 disclosed herein, 11 air pilot valves 7724would be required for a single filter unit associated with a singleslurry processing/analysis train or processing wedge 312.

The ultrafine filter unit 7700 may operate in accordance with thefollowing general procedure and method. The process described below maybe entirely automated and controlled in a sequenced manner by theelectronic system controller 2820 previously describe herein viasuitable program instructions executed by the controller's processor.Preferably, the filter unit is vertically oriented such that end 7715 isat top (i.e. top end) and end 7716 is at bottom (i.e. bottom end).However, other orientations of the filter unit may be used. Referencesbelow to open or closed ports of the filter unit are controlled by theair pilot valve 7724 associated with each of those ports unlessexplicitly noted otherwise.

To start the process, the slurry and extractant mixture is injected intothe filter via open slurry inlet port 7705 from the upstream slurryextraction manifold of the slurry analysis processing system at thepoint after the extractant has been thoroughly mixed with the slurry.This may be similar to the extraction point in the process shown in FIG.P-261 (slurry processing system 3000) or FIG. P-263 (slurry analysisprocessing wedge 312) using the ultrafine filter 5757 as previouslydescribe herein. This is represented in present FIG. 43 as theextractant mixing portion 7730 of the slurry processing system. Theslurry flows circumferentially around the filter media 7721 anddownwards in the annular slurry inlet plenum 7712 proximate to top end7715 of the filter unit towards the opposite bottom end 7716 of thefilter unit. During this process, the vent/overflow port 7708 is openedto allow residual air contained in the annular plenum to escape to wasteat atmospheric pressure during the slurry filling procedure (which mayinclude a small amount of slurry overflow).

The air pressurization-vent port 7726 is opened via a vent air pilotvalve 7724 shown in FIG. 43 to allow residual air in the internalfiltrate chamber 7714 inside the filter media 7721 to escape toatmosphere via air manifold 7728 fluidly coupled to port 7726 as shown.Both the filtrate chamber 7714 and slurry inlet plenum are thus ventedto ambient atmospheric pressure. The vent air pilot valve is fluidlycoupled with the air pressurization-vent port 7726 via air manifold 7728which also includes air pilot valves associated with a low pressure andhigh pressure air supply fluidly coupled to port 7726 as shown. Theseair supply pilot valves were initially and remain closed at this stageof the process.

Next, the filter unit and slurry outlet flow conduit 7725 (e.g. tubing)are primed. The priming filtrate waste air pilot valve 7724-2 fluidlycoupled to the slurry outlet flow conduit is opened. Slurry deliveredvia slurry inlet port 7705 to the filter unit fills the outer annularplenum 7713 and flows radially inwards from the plenum through filtermedia 7721 into the internal filtrate chamber 7714 via the pressure dropbetween the plenum and lower pressure filtrate chamber. The filtrate isdirected to waste via filtrate waste air pilot valve 7724-2 for a shorttime sufficient to prime the filter unit and slurry outlet flow conduit.It bears noting that the filtrate supply air pilot valve 7724-1associated with forwarding the filtrate/supernatant to the downstreamchemical analysis portion 7731 of the slurry processing and analysissystem is closed during the priming operation. After cessation of thepriming step, the low pressure air pilot valve and filtrate waste airpilot valve 7724-2 are closed.

After the priming step, the annular slurry inlet plenum 7713 ispressurized via establishing a high pressure filtering air flow tofilter pressurization air inlet port 7706 from a pressurized air source.The slurry passes through the filter media 7721 and into the internalfiltrate chamber 7714 where filtered slurry (filtrate) which forms thesupernatant for chemical analysis collects. It bears noting that thepressurized air source for all of the foregoing low and high pressureair to the internal filtrate chamber 7714 and high pressure air for theslurry inlet plenum 7713 may be a single source such as air compressor3030 and air tank 3031 shown in FIG. P-1, or another suitable availableair source previously describe herein. The air is supplied to thevarious air ports of the ultrafine filter unit 700 via appropriateconfigured and valved air conduits (e.g. tubing).

The filter is then again vented to ambient atmosphere by opening airpressurization-vent port 7726 fluidly coupled to the filter internalfiltrate chamber 7714 and vent/overflow port 7708 fluidly coupled to theannular slurry inlet plenum 7713. To supply the filtrate/supernatant tothe downstream chemical analysis portion 7731 of the slurry processingsystem, the low pressure air supply pilot valve 7724 and filtrate pilotvalve are opened. The reagent is then added to the filtrate/supernatantmixture and the level of analyte is then measured in the mannerpreviously describe herein.

Filter rinsing, backwash, and then air drying steps are performed toprepare the ultrafine filter unit 7700 for processing the next slurrysample. The rinse step is performed by opening the pressurized watersupply air pilot valve 7724 fluidly coupled to filter backwash inletport 7707 and lower waste ports 7709, 7711. The cyclonically swirlingstream of water forcibly removes the excess/residual slurry from theslurry inlet plenum 7713 while tangentially scrubbing residual slurryparticles from the outer surface of the filter media 7721. The backwashstep is performed by first injecting water from the pressurized watersupply through air pressurization-vent port 7726 into filtrate chamber7714. This forces water radially outward through the filter media 7721in the opposite radial direction than previously filtering the slurry.The water collecting in the slurry inlet plenum which contains slurryparticles dislodged from the filter media is directed to waste via thewaste air pilot valves. Water flow is terminated, and followed byapplying high pressure cleaning air pulses through the airpressurization-vent port 7726 into the filter unit internal filtratechamber 7714. This creates a hammering effect to knock any residualslurry particles off of the filter media 7721. This air pressureprovided by the high pressure air supply is higher than “filteringpressure” or “low pressure” air shown in FIG. 43 to facilitateappropriate micropore cleaning by dislodging small particles that wouldotherwise stay imbedded in the surface of the filter media due to a zeropressure differential across the media. The filtering air pressuresupply may be at an intermediate pressure which is higher than the lowpressure air supply, but lower than the high pressure air supplypressure. The low pressure air supply is at a pressure selected togently move the filtrate through and discharge it from the filter unit.The higher intermediate filtering pressure air supply is at a pressureselected to push the slurry through the filter media to produce thefiltrate. The still higher high pressure air supply is at a pressureselected to “back punch” the cleaning air in a second reverse directionthrough the filter media than producing the filtrate with sufficientforce to dislodge the particles entrapped on the filter. In someembodiments, cleaning pressure provided by the high pressure air supplyis preferably at least 1.5-2 times the filtering pressure to achievesatisfactory dislodgement and clearing of entrapped particles from thefilter media. The air dry step is then performed by opening the airpilot valve 7726 associated with the higher pressure air sources toallow “high” pressure air to push remnant water from filtrate chamber7714 to slurry inlet plenum 7713 while the “filtering” air fluidlycoupled to the inlet plenum 7713 then pushes the remnant water toatmospheric ports 7709, 7711 ports for wasting. This creates a vortexair flow drying effect within the filter. Drying may be facilitated inone embodiment by multiple tangential air inlet ports at the top of thefilter and multiple waste outlet ports normal to the unit at the bottomof the filter. Preferably, an even number of air inlet and waste outletports may be provided to balance the flow. This axial separation andoffset of ports at top and bottom along with a large volume of aircreates the vortexing action favored for fast drying in order to filterthe next slurry sample for the next analysis cycle in rapid succession.

The multiplexed pneumatic control air system shown in FIG. 42illustrates the combination of more expensive pneumatic control airvalves 7600 and greater number of less expensive air pilot valves 7724which provides a cost-effective solution to meeting the control airdemands of multiple ultrafine filter units 7700; each filter unitcomprising a plurality of associated air pilot valves for controllingthe multiple functional needs of the operational process describedabove. In the illustrated embodiment, each filter unit has 11 associatedair pilot valves (more or less may be used in other system variations).Because each air pilot valve of each filter unit has the same function,each function can be actuated simultaneously across all filter units bymultiplexing to produce a more economical control air system which isadvantageous for the present slurry processing system in which multipleslurry analyses are desired to be processed and chemically quantified inparallel for different analyte contained in the same agricultural sample(e.g. soil). This produces quicker results, allowing the nextagricultural sample to be processed sooner.

As an example for descriptive purposes only of the multiplexed pneumaticcontrol air system, FIG. 42 shows only four ultrafine filter units 7700for simplicity of illustration, which are designated 7700-1 to 7700-4.Each filter unit is shown having four ports and associated air pilotvalves 7724 identified as valves “1-4.” Each air pilot valve 1-4 isfluidly coupled to a respective upstream dedicated control air valve7600 designated 7600-1 to 7600-4 via a respective dedicated and fluidlyisolated shared air distribution manifolds 7703-1 to 7703-4. Forexample, air pilot valve 1 is fluidly coupled to and shares a firstshared air distribution manifold 7703-1, and so on for remaining airpilot valves 2-4 in this example. Each control air valve 7600-1 to7600-4 is fluidly coupled upstream in turn to a common air supplymanifold 7702 which is in turn fluidly coupled to a common air source7701, which may be air compressor 3030 and associated air tank 3031shown in FIG. P-1, or any of the other air sources previously describedherein.

An advantage of the present multiplexed pneumatic control air systemshown in FIG. 42 is that only the control air valve 7600-1 to 7600-4needs to be operably and communicably coupled to the system controller2820 in order to control the supply of control air to ultrafine filterunits 7700-1 to 7700-4 and air pilot valves “1-4” of each unit. Thisgreatly simplifies the control system wiring and controller programmingneeded to control the slurry filtration and post-filtration cleaningoperations of each filter unit described above. The control air systemallows multiplexing with electro-pneumatic valves that are sharedbetween similar functions of multiple analyses. When multiple analysesare present, each using their own filter(s), one common pneumatic signalcan be sent to as many filters as necessary so they all actuate eachfunction simultaneously, without requiring additional expensiveelectro-pneumatic valves for each incremental analysis.

In operation, as an example, when system controller 2820 ispreprogrammed and timed to initiate the same filter function associatedwith opening air pilot valve “1” of each of the four filter units 7700-1to 7700-4 (which may be any of the functions describe before) at thesame time, the controller transmits an electrical control signal tocontrol air valve 7600-1. Valve 7600-1 opens to transmit a control airsignal flow through shared distribution manifold 7703-1 simultaneouslyto each air pilot valve “1” of every ultrafine filter unit 7700-1 to7700-4. The air pilot valves are thus opened concurrently upon receivingthe control air signal. Cessation of the control air signal causes eachvalve to close concurrently at the appropriate time controlled by systemcontroller 2820. The same operational methodology applies to each of theremaining air pilot valves “2-4” which will be opened simultaneously atthe appropriate time by the controller.

Accordingly, the control air system allows multiplexing withelectro-pneumatic control air valves that are shared between similarfunctions of each filter unit for multiple analyses. When multipleanalyses are present and run in parallel, each using their ownfilter(s), one common pneumatic signal can thus be sent to as manyfilters as necessary so they all actuate each function simultaneously,without requiring additional expensive electro-pneumatic valves for eachincremental analysis.

In one aspect, a method for filtering a slurry may be basicallysummarized as comprising: providing the slurry filter comprising a bodydefining an internal central passage, a filter media arranged in thecentral passage and defining comprising an internal filtrate chamber andan annular slurry inlet plenum arranged defined between the body andfilter media; flowing slurry into the slurry inlet plenum at a first endof the body; pressurizing the slurry inlet plenum to force the slurryradially inwards through the filter media to deposit a filtrate in thefiltrate chamber; pressurizing the filtrate chamber to force thefiltrate to a filtrate outlet port at a second end of the body oppositethe first end.

In another aspect, a slurry filter unit for ultrafine slurry filteringmay generally comprise: a body defining centerline axis; a first end, anopposite second end, and an internal central passage extending betweenthe ends along centerline axis; a holder supporting an elongated filtermedia in the central passage, the filter media defining an internalfiltrate chamber and an annular slurry inlet plenum arranged definedbetween the body and filter media; a slurry inlet port oriented radiallyto the centerline axis at the first end and a filtrate outlet port atthe second end oriented parallel to the centerline axis; a filterpressurization air inlet port oriented radially to the centerline axisand fluidly coupled to the annular slurry inlet plenum for forcingslurry in the plenum radially through the filter media into the filtratechamber; and air port oriented parallel to the centerline axis andfluidly coupled to filtrate chamber for forcing filtrate to the slurryoutlet.

Microfluidic Process Fluid Mixing

When fluid passes from a large passage to a small passage abruptly,mixing occurs. This process may particularly be used with mixing ofslurry, extractants, reagents, or other fluids within the microchannelflow network in microfluidic processing disk 310. A group of micropumpsmay be provided for mixing. When mixing two constituents together toform one mixture for example, a micropump with associated pump chambercan be sized for the particular volume of each constituent necessary inthe required proportions to form the final mixture. A single largermicropump and chamber may further be provided which is sized to hole thetotal volume of the mixture comprised of two or more constituents.

In the non-limiting example shown in FIG. 41 and discussed below,pneumatically-actuated diaphragm micropump MP1 is sized for 2,500 μL ofagricultural slurry (e.g. soil slurry in one embodiment), micropump MP2is sized for 7,500 μL of extractant, and micropump MP3 is sized forbetween 10,000 and 10,200 μL of the combined mixture. The goal is forMP3 to always have a volume which can at least hold all of the fluidfrom micropumps MP1 and MP2. To account for manufacturing variability,micropump MP3 may be slightly higher in volume and displacement than thesum of MP1 and MP2. The foregoing micropumps may be formed and disposedin the layers of a slurry analysis processing wedge 312 of themicrofluidic processing disk 310 shown in FIG. 41 and previouslydescribed herein. The micropumps may comprise the entire wedge or only aportion of an individual processing wedge 312. Thepneumatically-actuated diaphragm micropumps are fluidly coupled togetherby the network of flow microchannels 322 and the pneumatically-actuateddiaphragm microvalves as described below. Microvalves used inmicrofluidic processing disk 310 such as pneumatically-actuateddiaphragm microvalves 328 were previously described herein.

Exemplary steps in a process/method for preparing and mixing aslurry-containing fluid will now be described. Reference made to an“open” pump chamber which follows means that the lower pump chamber 5765of the micropump MP1, MP2, or MP3 is open to its maximum volume forreceiving a fluid such as shown in FIG. P-257. The upper pump chamber5764 is not pressurized by control air via air inlet 5768 so thatdiaphragm 5763 is in an undeformed upward position, which “opens” thelower chamber to intake fluid for pumping. A “closed” pump chamber meansthat pressurized air is applied to upper pump chamber 5764 which movesand deforms the diaphragm 5763 to assume a downward position proximateto the bottom surface 5765-2 of lower chamber 5765 (see, e.g. FIG.P-258). This squeezes and pumps the fluid outwards therefrom via thefluid outlet port 5767 for further processing of the slurry mixture.

The process/method may be summarized as follows: (1) Open slurry inletmicrovalve 7650; (2) Open pump chamber of MP1 to pull a precise volumeof slurry equal to the displacement of MP1 into MP1; (3) Close slurryinlet microvalve 7650; (4) Open extractant inlet microvalve 7653; (5)Open intermediate microvalve 7654 between MP1 and MP2; and (6) Open pumpchamber of MP2 which causes suction through MP1 to pull extractant intoMP1 with the existing slurry creating a slurry-extractant mixture. Asextractant mixes with the slurry in MP1, some of the slurry extractantmixture enters MP2 until eventually MP2 is full and a quantity ofextractant equal to the displacement of MP2 has been drawn into thesystem and mixed with the slurry. The process continues with steps of:(7) Close extractant inlet microvalve 7653; (8) Close MP1 and open MP3simultaneously; (9) Close intermediate microvalve between MP1 and MP2;and (10) Close MP2. At this point, the entire quantity MP1+MP2 withprecise amounts of slurry+extractant have been mixed and combined intopump chamber MP3. The process is completed by the steps of: (11) Openoutlet microvalve 7656; and (12) Close pump MP3 to pump and forward themixed slurry/extracted sample mixture to downstream slurry processingphases such as tertiary/ultrafine filtration which may use for examplemicro-porous ultrafine filter 5757 shown in FIG. P-261, or anotherfilter. The ultrafine filter is configured to produce a clear filteredsupernatant capable of being chemically analyzed such as viacolorimetric analysis or another analytical technique used in the artfor an analyte of interest contained in the supernatant. It bears notingthat in FIGS. 41 , P2 and P3 are not isolated from each other by amicrovalve.

In FIG. 41 , micropump MP1 may further be fluidly coupled to microvalve7652 which controls the admission of a “standard” fluid used for testingthe accuracy of the slurry analysis system in general. The standard willcontain a known concentration (parts per million—ppm) of an analyte(e.g. nitrogen, phosphorous, etc.) which ultimately is measured via theflow analysis cell of the system previously described herein. MicropumpMP1 may further be fluidly coupled to water microvalve 7651 whichcontrols the admission of water into the micropump for periodicallyflushing out residual slurry remaining in the micropump lower pumpchamber.

Knife-Type Soil Sample Collection System

Traditional agricultural soil sample collection for the purposes ofnutrient analysis are performed with stationary systems requiring aninefficient investment in time and labor. This includes manualextraction of soil samples for testing. A machine powerednon-stationary, or “On The Go,” automated sample collection is desirablefor faster and less laborious collection.

According to the present automated mobile soil sample collection systemdisclosed herein, the system includes a collection apparatus comprisinga support frame and including one or more rotatable soil collectionspools configured to penetrate the soil for sample collection at timedpredetermined intervals. Each spool comprises a hollow tubular body withinternal collection cavity included in its cross sectional geometry tocapture a depth represented slice of soil and retain the sample. Spoolrotational actuation may be achieved with various methods including butnot limited to electric, pneumatic, or hydraulic power distributionusing motors and gear train, linear cylinders, rack and pinion,solenoids, and/or actuators alone or in any combination. For samplecollection, spools normally start in the down (i.e. into the soil) andclosed position to the soil which precludes entry of soil into thecollection cavity. At predetermined intervals, the spools alternatethrough cycles of rotating 180 degrees about their longitudinalcenterline. The collection cavity cycles and changes upon rotation ofthe collection spool between a concealed condition relative to the soil(soil collection cavity obscured or blocked), an exposed condition (soilsample captured), and back to concealed condition (captured sampleretained in spool). The sample collection apparatus may be controlled bya microprocessor-based system controller such as controller 2820previously described herein or another controller. The support framewith collection apparatus is configured for mounting on a poweredvehicle operable to traverse the agricultural field and collect samples“On The Go.”

FIGS. 44-82 depict one embodiment of a mobile soil collection samplesystem 8000 according to the present disclosure. The system comprises acollection assembly 8009 having a front 8005, rear 8006, left lateralside 8007, and right lateral side 8008 identified in FIG. 55 forconvenience reference in describing the assembly. The assembly 8009generally includes support frame 8001 and collection apparatus 8002movably mounted to and supported by the frame. Frame 8001 is configuredfor detachable mounting to the rear portion of any type of mobile pulledtrailer/equipment or self-powered wheeled vehicle 8003 operable totravel across the agricultural field AF containing soil to dynamicallycollect samples “On The Go” while the vehicle is moving. This differsfrom traditional stationary sampling techniques. Vehicle 8003 ifself-powered may be driven by a gas-powered, electric, or hybrid typeengine as some non-limiting examples. Vehicles 8003 may be used forsolely soil sample collection, or may be any type of general purposeself-driven wheeled vehicle or equipment commonly used in theagricultural arts such as pickup or other trucks, tractors, harvesters,etc. The type of powered vehicle or pulled trailer/equipment used doesnot limit the disclosure. Collection apparatus 8002 is configured to bepulled through the field by vehicle 8003 to collect samples in theembodiment depicted in FIG. 44 .

Support frame 8001 may generally comprise a forward-most primary framesection 8001-1 configured for direct or indirect detachably mounting orcoupling to the vehicle, a rearward-most collection apparatus framesection 8001-3, and an intermediate rail frame section 8001-2 mountedtherebetween which supports a carriage chassis 8058. Primary framesection 8001-1 may comprise a horizontally elongated mounting rod 8001-4configured for coupling to the vehicle 8003 in one embodiment. Rod8001-4 may be cylindrical in one embodiment. A plurality of mountingvibration dampers 8004 at the mounting locations to the vehicleaccommodate upward/downward movement of the collection apparatus 8002and reduce vibration as the collection apparatus penetrates and ispulled through the soil by the vehicle 8003. This avoids cracking of themounts. In one embodiment, springs 8004-1 may be used for the damperssuch a pair of dampers with springs: one spring mounted on each oppositeend of the rod 8004-1 as shown. Other numbers of dampers and mountinglocations may be used.

The intermediate rail frame section 8001-2 of support frame 8000supports carriage chassis 8058 which comprises vertically movablecarriage 8050 used to adjust the vertical position of the collectionapparatus 8002 relative to the surface or ground level of the soil andvehicle 8003. Collection apparatus 8002 is movably coupled to andsupported by the carriage as further described herein, which in turn issupported by the rail frame section. Rail frame section 8001-2 mayinclude a pair of laterally spaced and elongated vertical support rods8001-5, which may be rigidly coupled to horizontal mounting rod 8001-4by a plurality of substantially horizontal angled struts 8001-6. Thehorizontal struts support the rail frame section 8001-2 and collectionapparatus 8002 coupled thereto from vehicle 8003 in a cantileveredmanner. Struts 8001-6 may be mounted proximate to the top portions ofrods 8001-5 in one non-limiting embodiment. Rail frame section thusremains stationary relative to the primary frame section 8001-1 andvehicle 8003. Rods 8001-5 may have a tubular body with rectangular orsquare polygonal transverse cross-sectional shape in one embodiment;however, other polygonal and non-polygonal cross-sectional shapes (e.g.circular) may be used. The rods extend in the vertical direction betweenan upper mounting bracket 8051 and lower mounting bracket 8052. The topand bottom end portions of each rail 8001-5 are fixedly coupled to thebrackets in a rigid manner as shown.

Carriage chassis 8058 includes a pair of laterally spaced apart verticalguide rails 8027 rigidly coupled at each end to and supported from upperand lower brackets 8051, 8052 of the support frame intermediate railframe section 8001-2 via corresponding upper and lower chassis brackets8058-1, 8058-2 respectively. Rails 8027 are spaced rearward from andparallel to support rods 8001-5. The rails may be cylindrical withcircular transverse cross-section in one embodiment to engage thecylindrical rollers 8053 mounted to the carriage 8050, as furtherdescribed herein.

It bears noting that the various frame sections 8001-1, 8001-2, and8001-3 and carriage chassis 8058 described above may include a pluralityof additional subparts, components, fasteners, brackets, bearings,sleeves, collars, or other elements beyond the primary parts as shown inthe figures which may be necessary to perform their intended support andmounting functions. It is well within the ambit of those skilled in theart to provide such minor parts without undue elaboration here.

With continuing reference to FIGS. 44-82 , soil sample collectionapparatus 8002 may generally include knife assembly 8020 rotatablysupporting and housing at least one collection spool 8040 shown in thepresent embodiment being described, rotatable coulter blade 8021, spoolpositioning actuator 8024, knife positioning actuator 8026, rollingcarriage 8050 with carriage actuator 8029, and at least one guide ski8060 configured to slideably engage the ground or soil surface GS.Coulter blade 8021 is mounted forward and proximate to knife assembly8020 in one embodiment to create a trench or furrow in the soil throughwhich at least an upper portion of the knife assembly subsequentlypasses as the collection apparatus travels through soil. Samples arecollected from within the furrow. The blade initially breaks up andloosens the soil for the knife assembly which follows thereafter. Thishelps the knife assembly more easily as the assembly contains themovable collection spool. Knife assembly 8020 and coulter blade 8021 aresubstantially axially aligned with each other as best seen in FIG. 37 toaccomplish this. The term “substantially” as used here connotes that theknife assembly may be slightly offset laterally from the coulter bladealong the horizontal axis HA but functionally will still travel in andbenefit from the furrow created by the blade. As shown in FIGS. 44 and67-68 , the knife assembly 8020 and coulter blade 8021 partiallypenetrate the surface of the soil to a preselected depth for collectingthe soil sample.

Coulter blade 8021 may be formed of a generally circular metallic platein shape and may have a sharpened (i.e. taper or wedge shape) peripheraledge extending circumferentially around the blade body to better cutthrough the soil. In some embodiments, the blade may have a scallopeddesign as shown, or may be plain in other implementations. The coulterblade 8021 is rotatably coupled at its center to hub 8023 by a pair ofsupport arms 8022 laterally spaced apart on opposite sides of the blade.Arms 8022 may be vertically elongated each having a bottom end 8022-1coupled to one side of the hub in a manner which allows the blade 8021to rotate, and a top end 8022-2 fixedly coupled to the body of thecarriage 8050.

Carriage 8050 includes a plurality of rollers 8028 configured torollingly engage and move up and down along the guide rails 8027 (bestseen in FIGS. 79-80 ). The rollers may each have an arcuate concaverails engagement surface which is complementary configured to thecircular cross-sectional shape of the guide rails to maintain positivemutual engagement while the carriage travels up and down on the rails.To maintain smooth rolling engagement between the rollers and guiderails, in one embodiment, each of the rails may be engaged by verticallyspaced pairs of front rollers 8028-1, rear rollers 8028-2, and outboardside rollers 8028-3. The front and rear rollers stabilize movement ofthe carriage on the rails in the front to rear direction. The outboardrollers stabilize movement of the carriage in the lateral side to sidedirection. It bears noting that the set of rollers 8028 on carriage 8050further serve to ameliorate front to rear and side to side forces whichmay be imparted to the collection apparatus 8002 supported by thecarriage when the apparatus encounters rough and undulating soilsconditions or rocks at the soil surface GS; neither of which areunexpected in agricultural fields.

The vertical position of the carriage 8050 on guide rails 8027 iscontrolled by linear-acting carriage actuator 8029. Actuator 8029 isvertically oriented and may be arranged at the vertical geometriccenterline between the guide rails as shown. Actuator 8029 operates tolower or raise the carriage relative to the vehicle 8003 and in turnsoil surface GS of the soil (see, e.g. FIGS. 65-67 ). Accordingly, thedepth of penetration of the knife assembly 330 and coulter blade 331 ofcollection apparatus 312 into the soil is primarily adjusted by carriageactuator 8029 to which the collection apparatus is mounted in acantilevered manner. Actuator 8029 may be a pneumatic cylinder typeactuator in one embodiment; however, hydraulic cylinders or electriclinear actuators may also be used. The actuator 8029 is fixedly mountedto rail frame section 8001-2 at top and at bottom is operably coupled tothe rolling carriage 8050 via operating or piston rod 8029-1. Byretracting or extending the piston rod, the actuator 8029 selectivelyraises or lowers the carriage 8050 to which the entire collectionapparatus 8002 is mounted and supported relative to the vehicle 8003 andsoil surface. Actuator 8029 may raise the carriage 8050 and collectionapparatus 8002 mounted thereto to an upper stowed position for transportwhen not collecting soil samples (see, e.g. FIG. 69 ). In a lower activeposition actively engaged with the soil (see, e.g. FIGS. 67-68 ), thecollection apparatus is ready to collect soil samples.

For convenience of description, the collection assembly 8009 may beconsidered to define a vertical axis VA coaxial with the carriageactuator 8029 (passing through geometric centerline between guide rails8027) and a horizontal axis HA passing through the hub 8023 of thecoulter blade assembly (identified in FIG. 53 ). Whereas the verticalaxis remains fixed in position relative to the carriage chassis 8058 andcollection vehicle 8003, the horizontal axis is vertically movable withthe coulter blade 8021 and knife assembly 8020 as the carriage 8050moves up and down along the guide rails 8027. The elongated collectionspool 8040 defines a longitudinal axis LA (identified in FIG. 53 ) whichmay change between positions parallel to vertical axis VA and obliquelyangled to axis VA (see, e.g. FIGS. 67-68 ), as further described herein.

The collection apparatus 8002 (e.g. knife assembly 8020 and coulterblade 8021) is pivotably coupled to the pair of support arms 8022coupled to the carriage 8050 via a pivot arm linkage 8061. Linkage 8061has one end pivotably coupled to hub 8023 and an opposite end pivotablycoupled to pivot arm bracket 8055 fixedly mounted to the knife assembly8020. Bracket 8055 may be mounted to the larger front blade element 8031in one non-limiting embodiment further described below, preferably onthe top portion of the element which remains above the soil duringsample collection (see, e.g. FIGS. 46-47, 58 and 67 ). The knifeassembly 8020 of the collection apparatus has a pivot axis coincidingwith the horizontally oriented rotational centerline of coulter bladehub 8023. Knife assembly 8020 is moveable about its pivot axis in anarcuate path upwards and downwards (see, e.g. FIGS. 67-68 ).

Knife positioning actuator 8026 may be a pneumatic cylinder typeactuator in one embodiment; however, hydraulic cylinders or electriclinear actuators may also be used. Actuator 8026 is configured to act ina linear direction via movable operating or piston rod 8026-1 rotatablycoupled at bottom to the knife assembly swing arm bracket 8055 via aclevis and pin assembly 8056. At top, the top of the actuator housing ispivotably coupled to cross plate 8054 rigidly mounted between supportarms 8022 of the coulter blade assembly via pinned connection 8057. Theactuator 8026 supplies a holding force on the knife swing arm and can beused at at least partially set both the penetration depth of the knifeassembly 8020 and coulter blade 8021 in the soil, and the angle of theknife assembly relative to vertical axis VA.

The knife positioning actuator 8026 serves another useful purpose whichprotects the collection apparatus 8002 from damage. During use ofcollection apparatus when collecting a soil sample in the agriculturalfield AF, an obstruction in the soil may be encountered (e.g. rock,etc.) by the traveling collection apparatus 8002 (see, e.g. FIG. 67 ).In FIG. 67 , the piston rod 8026-1 is in an extended position relativeto the actuator housing with the knife assembly 8020 in an angledposition (e.g. front side of front blade element 8031 obliquely angledto vertical axis VA) for easier plowing/travel through the soil. Ifovercoming the obstruction when struck by the knife assembly and/orcoulter blade requires greater force than the holding force of theactuator can provide (e.g. air/oil pressure for pneumatic/hydraulicactuator or electric resistance for electric actuator), then the pistonrod of the actuator becomes compressed and retracts into the actuatorhousing, thereby pivotably tilting the knife assembly rearward andraising the collection apparatus to allow the obstruction to passbeneath the knife assembly (compare, e.g. FIGS. 67-68 ). The front sideof front blade element 8031 may be substantially parallel to verticalaxis VA now. The cylinder of the knife positioning actuator 8026 thusadvantageously serves as a shock absorber to provide a mechanicalcushion or “breakaway” mechanism for the collection apparatus whenencountering sub-surface soil obstructions to prevent damaging theequipment.

Knife assembly 8020 comprises a rear blade element 8030, front bladeelement 8031, top blade mounting bracket 8032, and bottom base plate8033. Base plate 8033 and mounting bracket 8032 may be horizontallyelongated with the blade elements sandwiched therebetween. The bladeelements are rigidly mounted at their tops to mounting bracket 8032 andat their bottoms to base plate 8033 via any suitable method, such as forexample without limitation threaded fasteners, welding, or other fixedmounting methods to provide rigidity to the knife assembly to counteractthe soil pressure applied by pulling the assembly through the soil forsample collection. The rear and front blade elements 8030, 8031 may bemounted to the base plate in a horizontally axially spaced apart manneralong horizontal axis HA of the collection apparatus to collectivelydefine a vertically elongated spool slot 8041 therebetween (best shownin FIGS. 42 and 43 ). Accordingly, slot 8041 is there collectivelydefined by the space created between each blade element. Slot 8041 has atransverse cross-sectional shape complementary configured to thecross-sectional shape of the spool 8040 which may be circular in oneembodiment (see, e.g. FIG. 48 ). Additional slots 8041 may be providedif more than one spool is incorporated into the knife assembly in otherembodiments, as further described hereafter. Spool slot 8041 isconfigured to rotatably and slideably receive the spool 8040 therein.Specifically, spool 8040 is vertically and slideably movableupwards/downwards in the slot, and rotatably movable as well forcapturing and retaining the soil sample as further described herein.Both the slot 8041 and spool 8040 may have circular shapes in transversecross-section as the spool may have a cylindrical configuration in theillustrated embodiment.

Rear and front blade elements 8030, 8031 may be formed of generally flatmetallic plates in one embodiment; each having opposing right and leftlateral major surfaces which are substantially parallel to each other.Any suitable overall general configuration of blade elements 8030, 8031may be used so long as the elements sufficient support and house thecollection spool 8040 and can penetrate the soil. The blade elements mayhave different shapes in perimetrical outline, which can be polygonal,non-polygonal, or combinations thereof. The front blade 8031 whichengages and plows through the soil head on may be larger and more robustto serve this functional purpose. The leading edge of front blade 8031may be angled or wedge shaped (in transverse cross-section) to betterplow through the soil. The smaller rear blade 8030 primarily functionsto define the spool slot 8041. It bears noting that the forward coulterblade 331 functions to partially loosen the soil before beingencountered by the knife assembly 8020 as it is pulled through the soil.However, the rear and front blade elements 8030, 8031 of knife assembly8020 extend vertically below the bottom of the coulter blade 8021 andguide ski 8060 (see, e.g. FIGS. 53-54 ) such the lower portion of theknife assembly encounters soil proximate to the bottom and just below ofthe furrow or trough plowed by the coulter blade. This soil layer may besomewhat loosed by the coulter blade to reduce frictional resistance onthe knife assembly thereby making is easier for the knife assembly toprogress forward through the soil to collect the soil samples.

Knife assembly 8020 includes guide ski 8060 which substantially limitsthe insertion depth of the knife assembly into the soil as seen in FIGS.67-68 . Ski 8060 has a horizontally elongated body and arcuatelyupturned front end to accommodate undulations in the soil surface of theagricultural field which naturally occur. The ski may be rigidly mountedto one lateral side of the knife assembly (e.g. front blade 8031) viacylindrical mounting boss 8062. In one embodiment, boss 8062 may bewelded to the top of the ski and to the side front blade 8031. Thiscreates a structurally robust attachment capable of maintaining theposition of the knife assembly 8020 against the soil surface GS and theholding force of knife positioning actuator 8026 (described elsewhereherein) when undulating soil surface conditions or surface debris (e.g.valleys, ridges, rocks, tree branches, etc.) not uncommon in theagricultural field are encountered by the collection apparatus 8002. Ski8060 may be preferably made of any suitable durable and strong metal.

FIGS. 48 and 57-66 show aspects of the soil collection spool 8040 andassociated spool drive mechanism in greater detail. In one embodiment,spool 8040 may have an elongated cylindrical body with a laterally andoutwardly open collection cavity 8042. The cavity may extend forsubstantially the entire length of the spool from top end 8043 to bottomend 8044. The top end is configured for mounting to spool positioningactuator 8024 which operates to selectively raise or lower the spool inthe knife assembly 8020. The bottom end may be closed to retain thecaptured soil sample. Cavity 8042 may have an arcuately curved contouror shape from side to side to facilitate removal of the captured sample.Spool 8040 may be formed of a suitable metal such as aluminum or steelfor ruggedness and durability for the service conditions. In oneembodiment, stainless steel may be used for corrosion protection toensure smooth rotational and linear movement of the spool in the spoolslot 8041 of the knife assembly 330.

Knife assembly 8020 further includes a spool drive mechanism operablycoupled to the collection spool 8040 which operates to (1) rotate thespool for capturing and retaining the soil sample, and (2) raise andlower the spool for ejecting the sample into a sample transport system.To accomplish the foregoing dual motions of the spool, the spool drivemechanism comprises a gear drive 8070 for rotational motion of the spooland a spool positioning actuator 8024 for linear up and down motion ofthe spool. Each motion and function will be described in turn below.

Gear drive 8070 comprises an electric motor 8072 including drive gear8074 coupled to the motor's drive shaft and intermeshed with a maindriven gear 8073 (see, e.g. FIG. 66 ). Driven gear 8073 is operablyinterfaced with the collection spool 8040, as further described herein.The drive gear and driven gear may be housed in gear box 8071 of anysuitable configuration for protection from the elements and environment.The gear box and motor may in turn be mounted on and supported by thegear drive support base or platform 8075, which may be attached to thetop of the knife assembly 8020. In some embodiments, the platform 8075may be configured for coupling to a sample collection/conveyance systemto transport the soil sample to the soil sample analysis system forslurry preparation and chemical analysis as previously described herein.Motor 8072 may be supported by the gear box and includes a drive shaft8074-1 coupled to drive gear 8074, shaft support bearing 8074-2, andshaft sleeve fitting 8074-3 supporting and surrounding the drive shaftbetween the drive gear and motor housing.

A pair of gear bearings 8076 of suitable type support the driven gear8073 for rotational movement (see, e.g. FIGS. 59 and 65 ). The drivengear assembly may include a tubular hollow drive sleeve 8073-1 insertedthrough central through passage 8073-2 of the gear hub 8073-3.Collection spool 8040 is received in and slideable upwards/downwardsthrough the through passage 8073-5 of the drive sleeve when the spool israised and lowered. Externally, the drive sleeve may include a pluralityof longitudinal splines 8073-4 which may be removably and insertablykeyed to mating longitudinal grooves 8073-5 formed inside the gear hubthrough passage 8073-2 to rotationally interlock the sleeve and drivengear 8073 such that the sleeve rotates in unison with the driven gear(see, e.g. FIGS. 59-60 ). The splines 8073-4 may be separate partsattached to the exterior of the drive sleeve in mating longitudinalslots as illustrated, or may be integrally formed as a unitarystructural part of the drive sleeve tubular body. Drive sleeve 8073-1 isintended to be an easily replaceable and less costly component than thedriven gear 8073 if replacement is required due to wear.

Drive sleeve 8073-1 forms an axially slideable but rotationallyinterlocked interface with the collection spool 8040 via sample ejector8081, which may be fixedly attached to the drive sleeve inside throughpassage 8073-5 of the sleeve by any suitable means. In one embodiment, apinned connection may be created by pins 8081-1; however, threadedfasteners or other means may be used for a fixed attachment. Ejector8081 may be mounted to the bottom end of the drive sleeve 8073-1 suchthat the upper pinned portion of the ejector resides inside the lowerportion of the drive sleeve taps 8073-5 while the wedge-shaped lowerportion protrudes downwards below the drive sleeve and driven gear (see,e.g. FIG. 62 ). Sample ejector 8081 is rotationally locked to and nestedat least partially within the collection cavity 8042 of collection spool8040 in a manner which allows axial longitudinal movement of the spoolrelative to the ejector. The ejector is configured and operable to ejectthe captured soil sample from the collection cavity for collection andfurther processing/analysis by the soil analysis system. The ejector8081 remains stationary in vertical position but rotatable with the geardrive while the collection spool 8040 can be selectively moved axiallyup/down by spool positioning actuator 8024 through the drive sleeve anddriven gear. Ejector 8081 may have an angled wedge-shaped scraper endconfigured to wedge the soil sample out from the collection cavity 8042of collection spool 8040 when the spool is raised.

The gear drive 8070 is operable to rotate the collection spool 8040 viaengagement with ejector 8081 between an open position for capturing asoil sample, and a closed position for retaining the captured sample. Itbears noting that as opposed to manually-operated handheld coreextraction devices or probes which vertically pierce the soil in anaxial direction, are pushed down to a desired depth, and collect a coresample that is simply retained in the tool as it is straight pulled backout, the present spool 8040 plows through the soil in a direction oftravel parallel to the soil surface GS. This captures the soil samplewhich is forced into the collection cavity 8042 in a directiontransverse to the longitudinal axis of spool LA and parallel to thedirection of travel of the collection apparatus as it (i.e. coulterblade and knife assembly) plows through the soil at a preselected depth.

Spool positioning actuator 8024 may be a pneumatic cylinder typeactuator in one embodiment; however, hydraulic cylinders or electriclinear actuators may also be used. Actuator 8024 may be supported bysubstantially vertical actuator support frame members 8024-2 from thegear drive support platform 8075 and/or knife assembly 8020. The supportframe is configured to coaxially align the piston rod with thecollection spool 8040 along the longitudinal axis LA of the spool.Actuator 8024 is configured to act in a linear direction via movableoperating or piston rod 8024-1 coupled via intermediate elements to thetop end of the spool 8040.

Referring particularly to FIGS. 59-60 and 65-66 , the bottom end of thespool positioning actuator piston rod 8024-1 may be rigidly coupled to ahollow tubular connector 8077 comprising a longitudinal through passage8077-1 extending between and through the connector body ends. In oneembodiment, a threaded coupling may be provided; however, other forms ofrigidly coupling including without limitation pinned connections, shrinkfit, threaded fasteners, etc. as some non-limiting examples. Connector8077 in turn is coupled to freely-rotatable swivel coupling 8078 whichis coupled to collection spool 8040. Swivel coupling 8078 includescollar 8080, fastening member 8079, and at least one or a pair ofbearings 8082 which rotatably support the fastening member. Collar 8080may be flanged comprising an annular radially protruding flange 8080-1which is fixedly attached to the bottom of connector 8077 by a pluralityof threaded fasteners 8080-2 such that the collar is not rotatablerelative to the connector. The fasteners member 8079 may be a threadedfastener in one non-limiting embodiment (as shown) which extends througha central passage 8080-3 of collar 8080 to threadably engage the top end8043 of the collection spool 8040. The top end of the spool is receivedin the lower portion of central passage 8080-3 to engage the fasteningmember 8079. Operation of the spool positioning actuator 8024selectively raises and lowers the collection spool 8040 between a lowerposition for capturing/retaining the soil sample and an upper positionfor rejecting the soil sample.

Referring to FIG. 65 , the connector 8077 and swivel coupling 8078 maybe assembled by first attaching the bearings 8082 and fastening member8079 to the top of the flanged collar 8080 and top end of the collectionspool 8040. The head of the fastening member and bearings are insertedthrough the bottom end of the connector through passage 8077-1. Thecollar flange 8080-1 is then fastened to the connector 8077, which trapsthe bearings and fastening member inside the connector via the flange ina rotatable manner.

A process or method for capturing a soil sample from an agriculturalfield using the collection apparatus 8002 will now be briefly described.FIG. 94 shows the complete cycle of the collection spool 8040 from startto finish through sample collection, retention, and ejection. First, thevehicle 8003 is driven or pulled to the desired starting location in theagricultural field. The collection apparatus 8002 is in an upperposition relative to the soil surface GS and vehicle during transport.The collection apparatus is then lowered to actively penetrate andengage the soil. The desired depth of penetration of the knife assemblyand coulter blade 8021 for collecting the soil sample may be adjustedand set by the vertical position of the carriage 8050 via operating thecarriage actuator 8029 as previously described herein. This may beperformed while the vehicle is stationary, or alternatively whilemoving. The angular orientation of the knife assembly 8020 may beadjusted by operating the knife positioning actuator 8026 as previouslydescribed herein. In one embodiment, the knife assembly may be set to anobliquely angled position to vertical axis VA of collection apparatus8002 (i.e. front side/edge of front blade 8031) to more readily plowthrough the soil (see, e.g. FIG. 59 ). The collection apparatuscomprises rotatable coulter blade 8021 and knife assembly 8020 arrangedproximate to the coulter blade and comprising at least one rotatablecollection spool 8040 comprising the collection cavity 8042. Thecollection spool may initially be in a lower position in the knifeassembly 8020, which may be a lowest position (see, e.g. FIG. 59 ) setby operating spool positioning actuator 8024 as previously describedherein. The bottom end of spool may therefore be positioned at thebottom end of the collection cavity 8042 engaging the top surface of thebase plate 8033. The collection cavity 8042 of collection spool 8040 mayfacing forward or rearward and shield from the lateral openings on eachside of the knife assembly 8020 at the spool slot 8041, as shown byPosition 1 in FIG. 94 .

The collection apparatus 312 (knife assembly 8020 and coulter blade8021) is then moved and plowed through the soil at the desired depth ina direction of travel parallel to a surface GS of the soil. The coulterblade creates a furrow or trough ahead of the knife assembly whichtravels at least partially therein for capturing the soil sample. At apredetermined time (which may be part of a preprogrammed timedsequence), the collection spool 8040 is then rotated full 180 degreesfrom (1) a first closed position via the first 90 degrees of rotation inwhich the collection cavity 8042 is shielded from the soil (see, e.g.FIG. 48 ) to a laterally open position in which the collection cavity isexposed to the adjoining soil so that the soil sample is captured in inthe collection cavity 8042, to a (2) opposite second closed/shieldedposition via the second 90 degrees of rotation for retaining the soilsample. This is represented by Position 2 in FIG. 94 . The collectionspool is rotated by gear drive 8070 at predetermined times to bothcapture and retain the soil sample. In some methods, the spool mayrotate continuously through the foregoing first closedposition—laterally open soil capture position—second closed positions.The rotational speed of the collection spool 8040 may be selected toallow sufficient time of soil to be forced into the exposed collectioncavity 8042. Alternatively, the spool may be first rotated 90 degrees tothe laterally open position, held in the open position for apredetermined period of time sufficient to allow soil to be forced intoand enter the collection cavity, and then rotated 90 further back to thesecond closed position for retaining the sample. Either approach may beused as needed and/or desired to collect a complete sample whichpreferably may fill at least a majority of the spool collection cavity8042 for its exposed length.

Once the soil sample has been captured, the collection spool 8040 may beraised while in the second closed position (Position 2, FIG. 94 ) to anupper position relative to knife assembly 8020 via actuation and linearoperation of spool positioning actuator 8024. As the spool is raised,the ejector 8081 exposed immediately below the driven gear 8073 in thegear drive support platform and above the top of the knife assembly 8020slides through and scrapes the sample out of the spool collection cavity8042 for capture by a sample collection/conveyance system for furtherprocessing to prepare the sample slurry and to ultimately chemicallyanalyze the slurry to quantify concentration of the analyte of interest.It bears noting that because the ejector 8081 is positioned above theknife assembly 8020, the sample may be positively ejected from the spool8040 while still in the second closed position without further rotationof the spool. Portions of the collection cavity 8042 above the knifeassembly are therefore exposed.

After the sample has been ejected, the method may continue by rotatingthe spool back to the first closed position (Position 1, FIG. 94 ) whilethe spool is still in the upper position, and then lowering thecollection spool 8020 in the knife assembly back down to the initiallower position. In alternative implementations of the method, the spoolmay be lowered without rotation while in the second closed position(Position 2, FIG. 94 ). Since both lateral sides of the knife assembly8020 are open at the spool slot 8041 as shown in FIG. 48 , the foregoingsample collection cycle may be repeated in the same manner previouslydescribed above but from the second lateral side of the knife assemblyas the spool is rotated from Position 2 back to Position 1. Using suchan approach, a sample may be collected with each 180 degree rotation ofthe collection spool 8040 and cavity 8040 from front to rear, and rearto front. This doubles the number of samples collected with each 360degree rotation of the spool. Accordingly, the spool need not be rotatedback to the initial starting position (Position 1) of the collectioncavity after sample ejection for each time a sample is to be collected.

It bears noting that the collection spool 8040 may be rotated in eitherdirection during the soil sample capture and ejection process. In someembodiments if reversible motors 8072 are used, the spool may rotate 90degrees in a first direction from an initial closed position to an openposition to capture the sample, and then rotate back 90 degrees in anopposite direction back to the same initial closed position to reclosethe collection cavity 8082 to retain the sample and raise the spool forsample ejection. Accordingly, numerous variations of the foregoingmethod are possible which are all contemplated by the presentdisclosure.

In a preferred but non-limiting embodiment referring to FIG. 59 , theforegoing sample collection process or method may be automaticallycontrolled by a programmable controller, such as without limitationsystem controller 2820 previously described herein or a separatededicated collection controller which may be operably linked to andcommunicating with the system controller 2820 to coordinate the entirecycle of sample collection, processing, and analysis. The carriageactuator 8029, knife positioning actuator 8026, and spool positioningactuator 8024 may thus be operably and communicably coupled to and underthe control of system controller 2820 which activates each actuator atthe desired time which may be preprogrammed and/or based on input from ahuman operator via any suitable wired or wireless electronicprocessor-based personal input device (e.g. smartphone, tablet, laptop,etc.) which establishes two-way communications. In the case of pneumaticor hydraulic actuators, it bears noting that control may comprise thesystem controller 2820 operating air or oil control valving associatedwith the actuator, which in turn controls operation of these typeactuators. In the case of electric linear actuators, the controller 2820may be directly coupled to and act on the actuator to electricallycontrol its operation. Various other control schemes are possible.

FIGS. 83-93 depict a two-spool embodiment of a collection apparatus8002A according to the present disclosure. The support frame 8001 andother elements of the collection assembly 8009 previously describedherein for the single spool embodiment of FIGS. 44-82 remain the same instructure and operation. They will not be described in repetitive detailagain for sake of brevity. Only additional or different aspects of thedual spool embodiment will be further described as necessary. Elementspreviously assigned numerical designations for the foregoing singlespool embodiment description have the suffix “A” added for the two-spoolembodiment presently being described.

The primary difference in the present two-spool embodiment is that twospools 8020A are rotatably supported by the knife assembly 8020A whichis modified to include two parallel elongated spool slots 8041A; oneeach rotatably and axially slideably receiving a spool. This allows agreater number of soil samples to be collected with each pass of theknife assembly through the field. In addition, the timing with whicheach spool 8040A will be open for collecting a sample, or closed forshielding the collection cavity 8042A or retaining a collected samplemay be timed via the system controller 2820 to ensure that only a singlesample is collected at a given time. Advantageously, one spool 8020A maybe in the lower position collecting a soil sample while the second spoolis in the upper position for ejecting the sample. The two spools thenalternate and switch position as the collection apparatus 8002A travels,thereby allowing samples to be collected with greater frequency for agiven distance of travel through the field by the knife assembly 8020A.For example, for 20 feet of linear travel of the vehicle 8003 andcollection apparatus 8002 in a row through the soil, twice the number ofsoil samples may be collected in comparison to the foregoing singlespool collection apparatus embodiment with a shorter linear distancebetween the collection points for each sample. When the samples areanalyzed by the system, this data can be used to generate greaterdetailed mapping of levels of soil nutrients (e.g. nitrogen, potassium,etc.) or other analyte of interest for the agricultural field. It bearsnoting that in some embodiments, more than two spools may be providedwhich are movably carried by the knife assembly to further reduce thedistance between soil sampling points in the field.

To accommodate independent rotary and axial linear motion of the twospools 8020A, a modified gear drive 8070A and separate spool positioningactuator 8024A are provided for each spool. It bears noting that only asingle carriage actuator 8029 and knife positioning actuator 8026 isagain needed for operation and deployment of the dual-spool collectionapparatus 8002A. The two-spool gear drive 8070A includes two sets ofelectric motors 8072A each with a rotatable drive gear 8074A and anassociated intermeshed driven gear 8073A, two drive sleeves 8073-1A eachrotationally interlocked with a driven gear 8073A, two sample ejectors8081A, and two sets of spool positioning actuator to collection spool8040A couplings each including a connector 8077A and swivel coupling8078A coupled thereto with the same previously described hereinsub-parts. It bears noting that each driven gear 8073A and drive gear8074A combination may act and rotate independently of the other therebyallowing the timing for rotating each spool to collect, retain, or ejecta soil sample be independently controlled

To accommodate two spools, the knife assembly 8020A is modified toincorporate two spool slots 8041A. Using the same fabricationmethodology as the single spool collection knife assembly 8020, thepresent dual spool knife assembly 8020A therefore comprises a rear bladeelement 8030A, front blade element 8031A, intermediate blade element8030-1A, and top blade mounting bracket 8032A and bottom base plate8033A. The rear, front, and intermediate blade elements may be mountedto the base plate in a horizontally axially spaced apart manner alongthe horizontal axis HA of the collection apparatus 8002A to collectivelydefine a pair of vertically elongated spool slots 8041A therebetween(see, e.g. FIGS. 89-91 ). The blade elements may have any suitableconfiguration and act in the manner shown in FIGS. 67-68 and previouslydescribed herein for collecting soil samples. The blade elements arefixedly attached to and between base plate 8033A and mounting bracket8032A in the same manner previously described herein (e.g. fastenersused for detachable coupling or welding used for permanent coupling).

Each collection spool 8040A of the two-spool collection apparatus 8002Aoperates according to the same method/process previously describedherein for the single spool embodiment, which will not be repeated herefor the sake brevity. The collection cycle may be controlledautomatically by the system controller 2820 in the same manner. Usingthe controller, the timing and sequencing for collection, retaining, andejection of the samples for each of the pair of spools may bepreprogrammed and automatically implemented in the manner previouslydescribed above.

In one embodiment, a method for capturing soil samples from anagricultural field may comprise: providing a collection apparatuscomprising a rotatable coulter blade, and a knife assembly arrangedproximate to the coulter blade and comprising rotatable first and secondcollection spool each comprising a collection cavity configured forcapturing soil samples; placing each of the first and second collectionspools in a first closed position; plowing through the soil at a depthwith the collection apparatus in a direction of travel parallel to asurface of the soil; rotating the first collection spool from a firstclosed position in which the collection cavity is shielded from the soilto an open position in which the collection cavity is exposed to thesoil to capture a first soil sample in the collection cavity; rotatingthe first collection spool to a second closed position for retaining thefirst soil sample; raising the first collection spool in the secondclosed position and ejecting the first soil sample from the collectioncavity; and simultaneous with raising the first collection spool,rotating the second collection spool from a first closed position inwhich the collection cavity is shielded from the soil to an openposition in which the collection cavity is exposed to the soil tocapture a second soil sample in the collection cavity of the secondcollection spool. The method may further comprise rotating the secondcollection spool to a second closed position for retaining the secondsoil sample; and raising the second collection spool in the secondclosed position and ejecting the second soil sample from the collectioncavity. The method may further comprise lowering the first collectionspool simultaneous with raising the second collection spool.

Examples: The following are nonlimiting examples.

Example 1, a micropump for a microfluidic device, the micropumpcomprising: a first layer; a second layer adjacent the first layer; aresiliently flexible diaphragm arranged at an interface between thefirst and second layers, the diaphragm having a peripheral edgeextending perimetrically around the diaphragm; and a first pump chamberformed on a first side of the diaphragm and a second pump chamber formedon a second side of the diaphragm; a plurality of restraining tabsprotruding radially inwards from the first layer into the first pumpchamber; wherein the restraining tabs abuttingly engage the peripheraledge of diaphragm.

Example 2, the micropump according to Example 1, further comprising anair inlet fluidly coupled to the first chamber, a fluid inlet fluidlycoupled to the second pump chamber, and a fluid outlet fluidly coupledto the second pump chamber.

Example 3, the micropump according to Example 2, wherein the restrainingtabs are perimetrically spaced apart from each other around a perimeterof the first pump chamber.

Example 4, the micropump according to any of Examples 1 to 3, furthercomprising a circumferential sealing channel recessed into the firstlayer around a perimeter of the first pump chamber, the sealing channelat least partially receiving the diaphragm therein.

Example 5, the micropump according to any of Examples 1 to 4, furthercomprising a raised annular lip arranged at an inner edge of the sealingchannel, the annular lip separating the sealing channel from a maincentral recess of the first pump chamber.

Example 6, the micropump according to any of Examples 1 to 5, furthercomprising a plurality of anti-stall grooves formed in the second pumpchamber.

Example 7, a method for assembling a micropump for a microfluidic devicecomprising: providing a first layer including a first pump chamber;positioning a resiliently deformable diaphragm on the first layer abovethe first pump chamber; positioning a second layer on the first layerand diaphragm; compressing the diaphragm between the first and secondlayers which causes the diaphragm to grow radially outwards; andengaging peripheral edges of the diaphragm with a plurality ofrestraining tabs arranged around the first pump chamber to restrain theoutward growth of the diaphragm.

Example 8, a method for preparing a slurry mixture in a microfluidicdevice, the method comprising: providing in the microfluidic device afirst micropump, a second micropump fluidly coupled to the firstmicropump by a first microchannel comprising a microvalve, and a thirdmicropump fluidly coupled to the second micropump by a secondmicrochannel; each of the micropumps comprising a chamber comprising apneumatically deformable diaphragm changeable between a closed positionfor discharging pumping a fluid and an open position for receiving thefluid; opening a slurry inlet microvalve fluidly coupled to the firstmicropump; changing position of the first micropump from the closedposition to the open position; drawing slurry into the first micropump;closing the slurry inlet microvalve; opening an extractant inletmicrovalve fluidly coupled to the first micropump; opening anintermediate microvalve disposed in the first microchannel between thefirst and second micropumps; changing position of the second micropumpfrom the closed position to the open position; drawing extractant intothe first micropump; and mixing the slurry and extractant form aslurry-extractant mixture.

Example 9, the method according to Example 8, further comprising drawingthe slurry-extractant mixture from the first micropump into the secondmicropump as a result of changing position of the second micropump fromthe closed position to the open position.

Example 10, the method according to Example 9, further comprising:changing position of the first micropump from the open position to theclosed position, and simultaneously changing position of a thirdmicropump from the closed position to the open position, the thirdmicropump fluidly coupled to the second micropump; and closing theintermediate microvalve between the first and second micropumps; andchanging position of the second micropump from the open position to theclosed position which pumps the slurry-extractant mixture into the thirdmicropump.

Example 11, the method according to Example 10, further comprisingchanging position of the third micropump from the open position to theclosed position which pumps the slurry-extractant mixture to anultrafine filter configured to produce a clear filtered supernatantcapable of being chemically analyzed for an analyte in theslurry-extractant mixture.

Example 12, a multiplexed pneumatic control air system for slurryfiltration, the system comprising: a plurality of filter unitsconfigured for filtering a slurry; each filter unit comprising aplurality of air pilot valves including at least a first air pilot valveassociated with a first functional purpose, a second air pilot valveassociated with a second functional purpose, and a third air pilot valveassociated with a third functional purpose; the first air pilot valvesof each filter unit fluidly coupled to a first shared air distributionmanifold fluidly coupled to a first electro-pneumatic control air valvefluidly coupled to an air source; the second air pilot valves of eachfilter unit fluidly coupled to a second shared air distribution manifoldfluidly coupled to a second electro-pneumatic control air valve fluidlycoupled to the air source; the third air pilot valves of each filterunit fluidly coupled to a third shared air distribution manifold fluidlycoupled to a third electro-pneumatic control air valve fluidly coupledto the air source; a system controller operably coupled to the first,second, and third electro-pneumatic control air valves to control aclosed and open position each electro-pneumatic control air valve; thecontroller being configured to transmit control signals to changeposition of the first, second, and third electro-pneumatic control airvalves to selectively initiate or stop a flow of air to the first,second, or third shared air distribution manifolds from the air source.

Example 13, the system according to Example 12, wherein the first airpilot valve of every filter unit is simultaneously changed betweenopened and closed positions by initiating or stopping the flow of air tothe first air distribution manifold.

Example 14, the system according to Example 12 or 13, wherein each ofthe first, second, and third air pilot valves of each filter unit isfluidly coupled to a different port of its respective filter unit.

Example 15, the system according to Example 14, wherein the first airpilot valves are fluidly coupled to a slurry inlet port of each filterunit, the second air pilot valves are fluidly coupled to a slurry outletof each filter unit, and the third air pilot valves are fluidly coupledto a filter pressurization air inlet port operable to drive slurrythrough a filter medium of each filter unit.

Example 16, the system according to any of Examples 12 to 15, whereinthe slurry is an agricultural slurry.

Example 17, a method for filtering a slurry, the method comprising:providing the slurry filter comprising a body defining an internalcentral passage, a filter media arranged in the central passage anddefining comprising an internal filtrate chamber and an annular slurryinlet plenum arranged defined between the body and filter media; flowingslurry into the slurry inlet plenum at a first end of the body;pressurizing the slurry inlet plenum to force the slurry radiallyinwards through the filter media to deposit a filtrate in the filtratechamber; pressurizing the filtrate chamber to force the filtrate to afiltrate outlet port at a second end of the body opposite the first end.

Example 18, a slurry filter unit comprising: a body defining centerlineaxis; a first end, an opposite second end, and an internal centralpassage extending between the ends along centerline axis; a holdersupporting an elongated filter media in the central passage, the filtermedia defining an internal filtrate chamber and an annular slurry inletplenum arranged defined between the body and filter media; a slurryinlet port oriented radially to the centerline axis at the first end anda filtrate outlet port at the second end oriented parallel to thecenterline axis; a filter pressurization air inlet port orientedradially to the centerline axis and fluidly coupled to the annularslurry inlet plenum for forcing slurry in the plenum radially throughthe filter media into the filtrate chamber; and an air port orientedparallel to the centerline axis and fluidly coupled to filtrate chamberfor forcing filtrate therein to the slurry outlet.

Example 19, the system according to Example 18, further comprising anair manifold fluidly coupled to the air port, the air manifold fluidlycoupled to a first air valve fluidly coupled in turn to a low pressuresource of air at a first pressure, and a second air valve fluidlycoupled in turn to a high pressure source of air at a second pressurehigher than the first pressure.

Example 20, the system according to Example 19, wherein the manifold isfurther fluidly coupled to a vent valve in communication with atmospherefor venting air from the filter unit.

Example 21, the system according to any one of Examples 18-20, furthercomprising filter pressurization air inlet port fluidly coupled to theslurry inlet plenum and a filter pressurization air valve.

Example 22, the system according to any one of Examples 18-21, furthercomprising a filter backwash inlet port fluidly coupled to the slurryinlet plenum and a filter backwash valve fluidly coupled to apressurized source of water, and a waste port fluidly coupled to theslurry inlet plenum at a location distal to the filter backwash inletport.

Example 23, the system according to any one of Examples 18-22, furthercomprising a programmable system controller operably coupled to thefilter unit and configured to control operation of the filter unit.

Example 24, a soil sample collection apparatus comprising: a supportframe configured for mounting to a vehicle; a collection apparatuscomprising: a coulter blade rotatably coupled to the frame; a knifeassembly coupled to the frame proximate to the coulter blade; and acollection spool movably mounted to the knife assembly, the collectionspool defining a longitudinal axis and comprising a collection cavityconfigured to capture a soil sample; a spool drive mechanism operablycoupled to the collection spool and configured to rotate the collectionspool; wherein the collection spool is rotatable between an openposition for capturing the soil sample, and a closed position forretaining the soil sample in the collection cavity.

Example 25, the apparatus according to Example 24, wherein thecollection spool has an elongated cylindrical tubular body and isrotatably and axially slideably received in a complementary configuredelongated slot in the knife assembly.

Example 26, the apparatus according to Examples 24 or 25, wherein thespool drive mechanism includes a rotatable gear drive operably coupledthe collection spool, the gear drive operable to rotate the spoolbetween the open and closed positions.

Example 27, the apparatus according to Example 26, wherein the spooldrive mechanism further comprises spool positioning actuator operablycoupled to the collection spool, the spool drive mechanism operable tomove the collection spool in a vertical axial direction between a lowerposition for capturing the soil sample, and an upper position forejecting the sample from the collection cavity.

Example 28, the apparatus according to Example 27, wherein the spoolpositioning actuator is electrically, pneumatically, or hydraulicallypowered.

Example 29, the apparatus according to any one of Examples 27 or 28,further comprising a sample ejector slideably disposed at leastpartially within the collection cavity of the collection spool, theejector configured and operable to eject the captured soil sample fromthe collection cavity when the collection spool is moved from the lowerposition to upper position.

Example 30, the apparatus according to Example 29, wherein the ejectorhas an angled scraper end configured to wedge the soil sample out fromthe collection cavity.

Example 31, the apparatus according to Examples 29 or 30, wherein thesample ejector is rotationally interlocked with the collection spool viathe collection cavity such that rotating the gear drive rotates thecollection spool in turn therewith between the open and closedpositions.

Example 32, the apparatus according to any one of Examples 29-31,wherein the sample ejector is fixedly mounted to the gear drive in astationary position relative to the collection spool such that as thecollection spool is raised or lowered, the ejector slides up and downwithin the collection cavity of the collection spool.

Example 33, the apparatus according to any one of Examples 26-32,wherein the gear drive comprises a motor having a drive gear and adriven gear operably interfaced with the collection spool via the sampleejector.

Example 34, the apparatus according to Example 27, wherein the spoolpositioning actuator comprises a piston rod operably coupled to thecollection spool, the piston rod extendible to lower the collectionspool in the knife assembly and retractable to raise the spool in theknife assembly.

Example 35, the apparatus according to Example 34, wherein the pistonrod is coupled to the collection spool by a swivel coupling, the swivelcoupling configured to allow the collection spool to freely rotaterelative to the piston rod when the collection spool is rotated by thegear drive.

Example 36, the apparatus according to Example 35, wherein the swivelcoupling comprises a collar fixedly coupled to the piston rod, and afastening member rotatably supported by the collar and fixedly attachedto the collection spool, the fastening member and collection spoolrotatable relative to the collar.

Example 37, the apparatus according to Example 36, further comprising atleast one bearing rotatably supporting the fastening member on thecollar.

Example 38, the apparatus according to Example 36, further comprising atubular connector fixedly coupled to the collar and piston rod top forma rigid connection therebetween.

Example 39, the apparatus according to Example 38, wherein the connectortubular comprise a longitudinal through passage which receives thefastening member of the swivel coupling therein.

Example 40, the apparatus according to any one of Examples 24-39,wherein the knife assembly is pivotably coupled to the coulter blade formovement in an arcuate path between a first angled position and a secondangled position.

Example 41, the apparatus according to Example 40, wherein the knifeassembly is vertically oriented in the second angled position andobliquely angled to vertical in the first angled position.

Example 42, the apparatus according to Examples 40 or 41, furthercomprising a knife positioning actuator operably coupled to knifeassembly, the knife positioning actuator operable to move the knifeassembly between the first and second angled positions.

Example 43, the apparatus according to any one of Examples 40-42,further comprising a pivot arm linkage pivotably coupled at oppositeends to a central hub rotatably supporting the coulter blade and theknife assembly.

Example 44, the apparatus according to Example 43, wherein the hubdefines a pivot axis of the knife assembly.

Example 45, the apparatus according to any one of Examples 24-44,wherein the collection apparatus is mounted to a movable carriagesupported by the support frame, the carriage vertically movable betweenan upper position for transport and a lower position for collecting thesoil sample.

Example 46, the apparatus according to Example 45, wherein the carriagecomprises a plurality of rollers which rollingly engage a pair of guiderails for raising and lowering the carriage and collection apparatus.

Example 47, the apparatus according to Example 46, wherein each guiderails is engaged by a pair of front rollers, a pair of rear rollers, anda pair of lateral outboard rollers to stabilize movement of thecarriage.

Example 48, the apparatus according to any one of Examples 45-47,wherein the carriage is coupled to a carriage actuator operable to raiseand lower the carriage on the guide rails.

Example 49, the apparatus according to any one of Examples 45-48,wherein the support frame comprises a substantially horizontal primaryframe section configured for direct or indirect detachable mounting tothe vehicle, a rearward-most collection apparatus frame section whichsupports the collection apparatus, and a substantially verticalintermediate rail frame section which supports a carriage chassis towhich the carriage is movably mounted.

Example 50, the apparatus according to any one of Examples 24-49,further comprising a second collection spool rotatably supported by theknife assembly and operably coupled to the a spool drive mechanism,wherein the second collection spool is rotatable independently of thecollection spool between an open position for capturing the soil sample,and a closed position for retaining the soil sample in a collectioncavity of the second collection spool.

Example 51, a method for capturing a soil sample from an agriculturalfield comprising: providing a collection apparatus comprising arotatable coulter blade, and a knife assembly arranged proximate to thecoulter blade and comprising at least one rotatable collection spoolcomprising a collection cavity configured for capturing the soil sample;plowing through the soil with the collection apparatus in a direction oftravel generally parallel to a surface of the soil; rotating thecollection spool from a first closed position in which the collectioncavity is shielded from the soil to an open position in which thecollection cavity is exposed to the soil; capturing the soil sample inthe collection cavity of the collection spool; and rotating thecollection spool to a second closed position for retaining the soilsample.

Example 52, the method according to Example 51, further comprisingraising the collection spool in the second closed position; and ejectingthe soil sample from the cavity.

Example 53, the method according to Example 52, further comprisingrotating the collection spool back to the first closed position afterthe ejecting step; and lowering the collection spool in the knifeassembly.

Example 54, the method according to any one of Examples 52 or 53,wherein the ejecting step comprises scraping the soil sample out of thecollection cavity of the collection spool with a stationary ejectorslideable within the collection cavity when collection spool is raised.

Example 55, the method according to Example 54, wherein the ejector isfixedly mounted to a gear drive operable to rotate the collection spoolbetween the closed and open positions, the ejector forming a rotationalinterlock with the collection cavity of the collection spool forrotating the collection spool via operation of the gear drive.

Example 56, the method according to any one of Examples 52-55, furthercomprising a spool positioning actuator operably coupled to thecollection spool and operable to raise and lower the collection spool.

Example 57, the method according to any one of Examples 52-56, whereinthe collection cavity of the collection spool faces forward or rearwardin the knife assembly when in the first or second closed positions, andfaces laterally outwards from the knife assembly when in the openposition.

Example 58, a method for capturing soil samples from an agriculturalfield comprising: providing a collection apparatus comprising arotatable coulter blade, and a knife assembly arranged proximate to thecoulter blade and comprising rotatable first and second collectionspools each comprising a collection cavity configured for capturing soilsamples; placing each of the first and second collection spools in afirst closed position; plowing through the with the collection apparatusin a direction of travel generally parallel to a surface of the soil;rotating the first collection spool from a first closed position inwhich the collection cavity is shielded from the soil to an openposition in which the collection cavity is exposed to the soil tocapture a first soil sample in the collection cavity; rotating the firstcollection spool to a second closed position for retaining the firstsoil sample; raising the first collection spool in the second closedposition and ejecting the first soil sample from the collection cavity;simultaneous with raising the first collection spool, rotating thesecond collection spool from a first closed position in which thecollection cavity is shielded from the soil to an open position in whichthe collection cavity is exposed to the soil to capture a second soilsample in the collection cavity of the second collection spool.

Example 59, the method according to Example 58, further comprisingrotating the second collection spool to a second closed position forretaining the second soil sample; and raising the second collectionspool in the second closed position and ejecting the second soil samplefrom the collection cavity.

Example 60, the method according to Example 59, further comprisingrotating the first collection spool back to the first closed positionand lowering the first collection spool.

While the foregoing description and drawings represent some examplesystems, it will be understood that various additions, modifications andsubstitutions may be made therein without departing from the spirit andscope and range of equivalents of the accompanying claims. Inparticular, it will be clear to those skilled in the art thatembodiments of the present disclosure may be embodied in other forms,structures, arrangements, proportions, sizes, and with other elements,materials, and components, without departing from the spirit oressential characteristics thereof. In addition, numerous variations inthe methods/processes described herein may be made. One skilled in theart will further appreciate that the embodiments of the presentdisclosure may be used with many modifications of structure,arrangement, proportions, sizes, materials, and components andotherwise, used in the practice of the embodiments of the presentdisclosure, which are particularly adapted to specific environments andoperative requirements without departing from the principles of thepresent embodiments of the present disclosure. The presently disclosedembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the embodiments of thepresent disclosure being defined by the appended claims and equivalentsthereof, and not limited to the foregoing description or embodiments.Rather, the appended claims should be construed broadly, to includeother variants and embodiments, which may be made by those skilled inthe art without departing from the scope and range of equivalents of theembodiments of the present disclosure.

1. A multiplexed pneumatic control air system for slurry filtration, the system comprising: a plurality of filter units configured for filtering a slurry; each filter unit comprising a plurality of air pilot valves including at least a first air pilot valve associated with a first functional purpose, a second air pilot valve associated with a second functional purpose, and a third air pilot valve associated with a third functional purpose; the first air pilot valves of each filter unit fluidly coupled to a first shared air distribution manifold fluidly coupled to a first electro-pneumatic control air valve fluidly coupled to an air source; the second air pilot valves of each filter unit fluidly coupled to a second shared air distribution manifold fluidly coupled to a second electro-pneumatic control air valve fluidly coupled to the air source; the third air pilot valves of each filter unit fluidly coupled to a third shared air distribution manifold fluidly coupled to a third electro-pneumatic control air valve fluidly coupled to the air source; a system controller operably coupled to the first, second, and third electro-pneumatic control air valves to control a closed and open position each electro-pneumatic control air valve; the controller being configured to transmit control signals to change position of the first, second, and third electro-pneumatic control air valves to selectively initiate or stop a flow of air to the first, second, or third shared air distribution manifolds from the air source.
 2. The system according to claim 1, wherein the first air pilot valve of every filter unit is simultaneously changed between opened and closed positions by initiating or stopping the flow of air to the first air distribution manifold.
 3. The system according to claim 1, wherein each of the first, second, and third air pilot valves of each filter unit is fluidly coupled to a different port of its respective filter unit.
 4. The system according to claim 3, wherein the first air pilot valves are fluidly coupled to a slurry inlet port of each filter unit, the second air pilot valves are fluidly coupled to a slurry outlet of each filter unit, and the third air pilot valves are fluidly coupled to a filter pressurization air inlet port operable to drive slurry through a filter medium of each filter unit.
 5. The system according to claim 1, wherein the slurry is an agricultural slurry. 